Cold war enemies Russia and the United States came together on Wednesday to sign a landmark nuclear arms treaty. The treaty commits both states to reducing their strategic warhead stockpiles to 1,500: 30% lower than previous limits, as dicatated by the 2002 Mosow Treaty. At a joint press conference, U.S President Barack Obama described the deal as “an important milestone for nuclear security and non-proliferation.” Russian President Dmitry Medvedev touted as a “win-win situation” that would lead to better bilateral relations. Further talks between both sides will take place this summer. Seems like smooth sailing from here—except that on Tuesday, Russia’s foreign minister warned that the treaty could be abandoned if the US continues with its desired missile defense system in Europe.