Russian President Vladimir Putin has done wonders for NATO. He has united the alliance in a manner not seen since the Cold War. Moreover, were it not for his invasion of Ukraine, neither Finland nor Sweden would likely have applied to join the alliance. Finland has become a member; Sweden may join now that Recep Tayyip Erdogan has been reelected president of Turkey. Erdogan no longer needs to play to the anti-Kurdish impulses of the country’s extreme nationalists, whose party leader threw his support behind him during the second round of elections. Some NATO officials speculate that Erdogan will reverse...