In response to the political turmoil surrounding the recent refugee crisis, destination countries swiftly implemented new immigration and asylum policies. Are such countercrisis policies effective in mitigating political instability by reducing anti-immigrant backlash and support for radical-right parties? The present study exploits two surveys that were coincidentally fielded during significant policy changes, sampling respondents right before and immediately after the change. I employ a regression discontinuity design to identify the short-term causal effect of the policy change on public opinion within a narrow window of the sampling period. The findings show that both Swedish border controls and the EU–Turkey agreement significantly reduced public opposition to immigration in Sweden and Germany, respectively. In Germany, support for the AfD party also decreased following the new policy. Public opinion time trends suggest that the policy effects were short lived in Sweden but durable in Germany. These effects are similar across different levels of proximity to the border and are accompanied by increasing political trust and a sense of government control over the situation. The findings have implications for understanding the impact of border controls on international public opinion, as well as for assessing the electoral effect of policy responses to global refugee crises.