Making decisions on grand strategy takes courage: vital interests are at stake, so the consequences of failure may be grave, especially if one is engaged in active rivalry with another power. This is a different kind of courage than gallantry on the battlefield, of course; it is the courage to take responsibility, which is a requirement for strategic success, as Sir Hew Strachan notes. Every decision is based on imperfect information, and one can never fully know the intentions of the other powers – the fog of diplomacy is as real as the fog of war. Accepting a degree of risk is inevitable, therefore, or one would never make any decision – and indecision and inaction have consequences too. The French and British policy of non-intervention in the Spanish civil war (1936–39) in practice amounted to a weakening of the legitimate Republican government, for Italy and Germany did militarily support Franco's rebellion, and London and Paris had no intention of stopping them. In such cases one must agree with Talleyrand, who defined nonintervention as ‘a metaphysical and political term that means more or less the same as intervention’. Sometimes, of course, not acting really is the best course to take. But not acting must be a conscious decision, because one assesses that one's interests are not sufficiently at stake to warrant action; it must not be the result of inertia or mere risk aversion.

In grand strategy avoiding failure is not necessarily the same as success. By escaping from the European continent through Dunkirk, the UK between 26 May and 4 June 1940 narrowly avoided the destruction of the British Expeditionary Force. That was justifiably celebrated as a remarkable achievement, but as Churchill dryly remarked: ‘Wars are not won by evacuations.’ Real success means achieving one's ends, which one must define in a sufficiently ambitious way to safeguard one's interests in the first place. That end, in 1939, had been to defeat Germany and restore the independence of Poland; instead, by sitting tight in defensive positions during the ‘phoney war’ and leaving the initiative to Germany, France and the UK invited failure.

A persuasive grand strategy usually is simple. A grand strategy is a mission statement rather than a manual. The core of grand strategy is a view of the state's role in international politics, the few large ends that it sets out to achieve, and a broad idea of how to go about that. The details are for the geographic and thematic strategies that should follow on from a grand strategy. With a bit of effort and goodwill, a grand strategy can be elegantly expressed in a few brief pages, though few states manage that. ‘I didn't have time to write a short letter, so I wrote a long one instead’, the saying, often attributed to Mark Twain, applies to the drafters of strategy as well (though academics are not well placed to criticise others for writing too much).

That, ideally, a grand strategy is simple does not mean that it will be easy to bring into practice. ‘Everything is very simple in war, but the simplest thing is difficult’, said Clausewitz, by which he meant difficult to implement. Clausewitz had served in the Napoleonic wars. Field Marshal Erich von Manstein, who served in the Second World War, similarly concluded that ‘in war the simplest thing often turns out to be the most difficult. Not in the decision as such, but in its unfailing implementation mostly lie the true difficulties.’ These statements apply to grand strategy in war and peace. If the grand strategy itself is already too complicated to explain to those who have to implement it, it is most probably not a very good strategy, and will likely never be implemented as intended at all. If, conversely, a straightforward strategy based on a simple idea is well communicated, it will serve to inspire those charged with its implementation, and provide them with a sense of purpose and the resolve to achieve it. ‘Action at the service of a strong and simple idea’, thus Charles de Gaulle summed up his policy in the Second World War.

In addition to good ideas, grand strategy requires clear language. Sir Lawrence Freedman stresses that strategy is meaningless without it: ‘Not only does strategy need to be put into words so that others can follow, but it works through affecting the behaviour of others.

Every state has political, economic and security interests, just like every issue in international politics has a political, economic and security dimension. Grand strategy has to be comprehensive, therefore, and tackle all three dimensions at once. A strategy that defines ends in only one dimension while ignoring the others is unlikely to achieve durable results. A state that does not develop instruments and muster resources in all three dimensions will soon run into situations in which it has no way of acting. A great power must thus surely be a power in political, economic and military terms in order to sustain its ambition to have global impact. Political power, that is the attractiveness of one's way of life as well as one's influence in another state or in an organisation (which can acquired by legal or illegal means), allows one to convince others to act in accordance with one's interests. Economic power can be a carrot as well as a stick, to entice another state or to coerce it, by offering or withholding trade, investment and development cooperation, or access to one's domestic market. Military power too can entice as well as coerce, offering assistance or threatening war.

Convincing, enticing and coercing, or hard and soft power, go hand in hand. The best strategists manage to convince the other so that they do not have to revert to coercion. but it is easier to convince or entice when the opposite party knows that you have the power to coerce it (through economic or military ways) if you decided to, even if the option is not openly put on the table. Diplomacy does not always need to be directly underpinned by economic and military power to be successful; a small state that acts as an honest broker can achieve remarkable success – but the actual parties to the negotiations will be aware of the balance of power and how they will fare if they do not find agreement. ‘Diplomacy, underneath the conventions of form, recognises only realities’, concluded De Gaulle. Vice versa, the result of coercion will probably be more durable if afterwards the opposite party can be enticed into accepting it by the offer of political and economic benefits.

When a state adopts a strategy to increase employment or to prevent pollution on its own territory, it has no rivals. Of course, certain citizens, employers, trade unions or pressure groups may have other ideas and try to thwart the government's plans. But there is no other state or entity with the legal authority to adopt an alternative strategy for the same issues on the same territory. In domestic politics, every state reigns supreme. If another state does try to interfere, that constitutes an act of subversion, which will likely result in retaliation.

International politics, in contrast, is inherently competitive: states operate alongside each other in the same geographic theatres, international organisations and thematic policy areas, each pursuing its interests through its own grand strategy. The competitive nature of grand strategy is probably its most obvious characteristic, and yet it is often forgotten that the other players have a strategy too, or they are underestimated. ‘Always remember, however sure you are that you can easily win, that there would not be a war if the other man did not think he also had a chance’: Churchill's quote applies just as much to peacetime grand strategy. Great powers and other states alike, when designing strategy, must take into account not only the limitations imposed by their own resources and the constraints of the environment, but also the fact that other players will be pursuing a proactive grand strategy of their own. As General Montgomery, frustrated with the state of planning, wrote to General Alexander prior to the allied landing in Sicily in 1943: ‘I have been ordered to invade the mainland of the continent of Europe on the 30th August. In the absence of information to the contrary, I must assume that some resistance will be offered by the enemy.’

States cannot be but competitors, as they seek influence, partners, markets and resources in the same countries and organisations. Such competition is natural; economic competition, moreover, is inherent to capitalism. Normal competition can turn into rivalry, however, if one state perceives foul play by another. A state that does not apply reciprocity, bending or evading the rules that other states observe, or that seeks to fence off markets and resources for its own exclusive use, may provoke the active rivalry of its competitors.

Rarely has a state safeguarded its vital interests by passively waiting for things to come. As A.J.P. Taylor wrote: ‘Those who really know what they want, get it – not necessarily of course in the way that they want, but they get it somehow. But those who hesitate between different objectives and seek only some compromise which will postpone difficulties, get nothing – not even the postponement they long for’. A state may, of course, adopt a defensive grand strategy in the face of current and expected threats and challenges. Or it may opt for an offensive approach, grasp the initiative, and seek to change its environment. Either way, be it for offence or for defence, a state must prepare to act: those that are not proactive will be forced to react to the strategic moves of the others. In war, if one can get into the decisionmaking cycle of the enemy, that is make the next move before the opponent has even had time to digest and react to the previous move, success is nearly always guaranteed. In 1940, French command and control was methodical, but slow, geared to the speed of operations of the First World War. As a result, France was systematically outpaced – rather than outgunned – by the German armoured formations. The American armed forces achieved a similar feat against their Iraqi counterparts in the two Gulf Wars, in 1991 and 2003. The same rule applies to grand strategy overall: the state that holds the initiative and sets the pace has the advantage over the others. Vice versa, once stuck in a reactive mode, it is difficult to focus on one's own ends.

The very definition of a great power implies proactivity: the ambition to have a global impact cannot be realised otherwise. Proactivity should not be mistaken for aggressiveness, however: rather than in undermining or attacking its rivals, a power can also be proactive in forging alliances and partnerships, and in improving its own competitiveness. Setting out a constructive agenda in the mutual interest of various powers takes as proactive an approach as launching a military intervention. If, however, the great powers ignore the opportunities for cooperation and focus exclusively on competition and rivalry, they risk bringing about a world ruled only by Thucydides’ dictum: the strong do what they will and the weak suffer what they must.

‘There is only one thing worse than fighting with allies, and that is fighting without them’, said Winston Churchill near the end of the Second World War. An alliance in the strict meaning of the term is a commitment between states to support each other in war. Europeans and Americans will immediately think of NATO and collective defence: a long-term if not permanent alliance to defend each other in case of aggression against a fellow member. But an alliance can also be concluded for a specific short-term purpose; and that purpose can be to make war. The great powers need allies and partners in all dimensions of international politics though, not only in the military sphere. They seek partners who will work with them to bring their particular view of the world order into practice, for example by voting along with them in existing international organisations, by joining them in creating new multilateral institutions, and by aligning their economic practices.

If one is in an alliance, one must consult one's allies, decide together, and take action together when the purpose of the alliance is at stake. That inevitably takes more time than when one acts alone, and may lead to compromise decisions. After the 1999 NATO air campaign against Serbia, to force an end to the violence in Kosovo, the US complained of the inefficiency of such a ‘war by committee’. But allies bring additional resources, and may also add legitimacy to one's actions: the more support a strategy garners from other states, the more acceptable it will appear to the domestic and international audience. When US President Barack Obama created the global coalition against ISIS in 2014, from the start he sought the participation of a number of Arab countries in order to create the perception of a truly international rather than a western initiative, and he consciously avoided the label of the US’ standing alliance, NATO. Eventually, the coalition recruited 82 members – not out of military necessity, but for political reasons.

‘No operational plan extends with any certainty beyond the first clash with the main enemy forces’, taught Field Marshal Helmuth von Moltke, architect of military victory in the wars of German unification that Bismarck triggered between 1864 and 1871. Or, as Field Marshal Slim put it more laconically: ‘I should have remembered that battles, at least the ones I had been engaged in, very rarely went quite according to plan.’ It is another military adagio that applies to grand strategy as a whole. The other players have a strategy too, hence implementing one's own strategy requires agility: the willingness and the decision-making structures to rapidly and flexibly adapt strategy to changing circumstances. Deciding on grand strategy usually requires long debates and complex procedures, however, involving many entities within the state: different parties or factions, different ministries, the armed forces. Once the decision is taken, those players usually are reluctant to make great changes, for fear of upsetting the equilibrium between them, or of domestic political consequences. It is only human that the people who have signed off on the strategy become attached to their ‘beautiful’ strategic concept and their ‘perfect’ plans – but that is a decidedly unstrategic attitude. The principles of grand strategy may be summarised in ten words and carved into stone (or so I pretend), but actual strategy should be subject to constant assessment and review. ‘A little more time, a little more help, a little more confidence, a few more honest men, the blessing of Providence and a rather better telephone service – all would have been well!’: every scheme can be a close run thing, as Churchill indicated. And if it does go wrong, one needs to adapt fast.

One way of ensuring a regular review is to institutionalise it, and to enshrine in law that a new grand strategy must be adopted at fixed intervals. As seen in Chapter 1, every US president has a legal obligation to present a National Security Strategy. In China, the five-yearly congress of the CCP provides a regular framework. No equivalent obligation exists in Russia, but Moscow issues new strategies regularly.

Making strategy is a rational process: an objective analysis of how much power one has, and how much power one's competitors and rivals have, determines which ends are feasible. Strategists make mistakes, of course. Their assessment of the environment can be wrong, they can misread the strategies of the other players and under- or overestimate their resources, they can fail themselves to commit the resources required and implement what they decided. Or they can be outwitted by the strategists of another state. If the premises of a strategy turn out to be false, or a competitor or rival is more successful, strategy must be revised through the same rational process. ‘But governments and people do not always take rational decisions. Sometimes they take mad decisions, or one set of people get control who compel all others to obey and aid them in folly’, Churchill points out. History is full of examples of leaders who allowed religion, ideology or emotion to trump reason, overreached, and failed.

Philip II, Catholic King of Spain from 1556 to 1598, trusted in divine providence rather than heeding his advisors who warned of the lack of resources to make war simultaneously on protestant England, the rebellious protestant provinces of the Netherlands, and the ‘infidel’ Ottoman Empire. The results of this overreach were dramatic. The Spanish armada sent against England was sunk in the Channel (1588). The northern Netherlands, the United Provinces, became an independent republic and a great power, and would enjoy a ‘golden century’ (not least thanks to the influx of refugees and wealth from what remained of the Spanish Netherlands on the territory of current-day Belgium, I cannot refrain from pointing out). The Ottoman conquests were but briefly delayed before the empire continued its expansion.

Truly catastrophic was the result of Hitler's decision to invade the Soviet Union, after having failed to defeat the UK. Launching operation Barbarossa (22 June 1941) was logical within Hitler's own ideologically determined worldview; the destruction of bolshevism had been his avowed aim since the publication of Mein Kampf in 1925. But the decision was not rational when looking at the reality of a two-front war and the limits on German resources.

I am only an academic, so the pressures of command on me are somewhat lesser, but like General Eisenhower I dare not claim credit for every idea in this book. I am a double-hatted academic, dividing my time between Ghent University and a think-tank, the Egmont–Royal Institute for International Relations in Brussels. That privileged position puts me in permanent contact with a wide variety of interesting people: students and faculty at my own and other universities; colleagues in think-tanks in Europe, the Americas, and Asia; and military officers, diplomats and officials working for the European Union, NATO, and their member states, and the various states represented in Brussels, the diplomatic capital of Europe. I am indebted to a great many colleagues from these various communities, many of whom have become friends, for sharing their insights. Our ongoing discussions serve to generate ideas and to sharpen my thinking. More often than not, the most stimulating discussions take place over a glass or a meal. We Belgians adhere to the dictum of Napoleon's foreign minister, Talleyrand: ‘Good dinners make for good reporting’.

Fortified though I may feel for being a member of this inspiring community, writing a book on the big topic of the grand strategies of and relations between the United States, China, Russia and the EU remains a risky undertaking. I certainly do not pretend to be an expert on all of these players and all of their policies. For a start, I speak neither Chinese nor Russian. The key primary documents, such as a national security strategy, are available in English, but I can only scratch the surface of the rich intellectual debate that is going on within both countries, of which the English-language publications by Chinese and Russian scholars offer but a glimpse.

Everyone involved in making strategy must accept that inevitably they will have to face circumstances in which there are no ‘good’ options: a situation in which every course of action, as well as inaction, risks to produce specific negative effects for one's interests. The strategist will still have to make a rational choice, and identify the lesser evil: the option that presents the best chance of safeguarding the vital interests of the state. The reticence to make stark choices even though the situation demands it is understandable, for the decision makers will be held accountable for the potential negative consequences – but it goes against the precepts of grand strategy. A state cannot retreat from international politics and fence itself off from the world: it will have to play its part. Even if a state foregoes an active role, it will for sure be the object of the strategies of its competitors and rivals.

The history of my own country, Belgium, exemplifies how it is an illusion to think that one can escape from reality. In 1830 the great powers recognised Belgium's independence from the Netherlands, but imposed neutrality on the new state. The powers did not trust one another: by forbidding the Belgians from entering into an alliance, they made sure that none of them would dominate the kingdom. Neutrality shielded Belgium from the Franco-Prussian war in 1870. Afterwards, neutrality was raised into a dogma: the Belgian strategic establishment became convinced it would protect the kingdom forever – but in 1914 Germany violated neutrality and invaded. Following the war, the Treaty of Versailles did away with compulsory neutrality, and Belgium concluded a military agreement with France. Yet in 1936, when the threat of war was clearly rising as Nazi Germany was rearming, the country opted for neutrality again, voluntarily this time, in the vain hope that the war that by then everyone expected would pass it by. The experience of the Great War ought to have taught the strategic establishment that this was not a realistic strategic option: it was clear that any German offensive against France would once again seek to pass through Belgium. The kingdom could not stand aside from the world, and so the result of retreating into its own bubble was still the same: in 1940 Belgium was invaded a second time.