In the weeks since July’s NATO summit in Vilnius, Western debate about Ukraine’s long-term security arrangements has fallen into three categories. The country’s most bullish backers want it to become a NATO member and enjoy the alliance’s protection, even though Kyiv did not receive a formal invitation to join at the summit. Their critics respond that admitting Ukraine into NATO will only up the ante and risk all-out war with Russia and that the West should persuade Kyiv to settle the conflict. Seeking a middle ground, a third group proposes that the West should continue providing