Avoiding war, while securing nation’s vast global interests, is a perennial challenge for any United States president. This is especially true in today’s fraught international climate, when there are no shortage of flash points that could rapidly draw the nation into military conflict. But throughout history forward-looking statesmen like FDR, Gorbachev, Rabin, and Walesa – leaders who anticipated change and were willing to build alliances and engage with adversaries – were able to promote peace under testing circumstances. What would such a strategy of preventive engagement look like for the United States today? And what are the risks of such an approach to international relations?