The U.S. is afraid of losing in Ukraine -- or winning

Mr. Putin fears also the things that Ukraine might do to which he might have to respond—as does the U.S., which is why it discourages strikes on Russia proper. The Kremlin has warned of ominous consequences if Ukraine bombs a vital bridge in Crimea. Monday’s special-forces attack on a Russian air base in Crimea may fall in the same category depending on how Mr. Putin chooses to react. And remember Mathias Rust, the German pilot who landed his Cessna on Red Square at the height of the Cold War? Neither the Kremlin nor the U.S. can have confidence in Russian air defense to stop a Ukrainian MiG bent on bombing Moscow’s onion domes or Mr. Putin’s private office.

None of this means the West shouldn’t up its support—just the opposite. But be ready for what it entails. The problem with some of the go-for-victory calls is their magical element—the unspoken stipulation that Ukraine can supply victory without NATO getting its feet wet. NATO will have to get its feet wet if it wants anything other than a frozen conflict that carries on without resolution (unfortunately the preferred outcome of many in the West). Mr. Putin can’t lose to Ukraine, he has to lose to NATO. In their separate recent war updates, the Atlantic Council and Rand Corp. both emphasize the possibility of the Kremlin leader seeking an armed confrontation with the U.S. to rescue his position at home.