How Solid Are U.S. War Guarantees?

When several NATO nations revealed that they had dozens of Russian-made MiG-29s, the idea arose to fly them to Ukraine and turn them over to Ukrainian pilots familiar with the MiGs.

America would provide F-16s to replace the MiGs.

Poland had an even better idea. Warsaw would fly its 27 MiG fighter jets to the U.S. Ramstein Air Force Base in Germany. The planes would be turned over to the Americans there, repainted and flown to Ukraine.

How to get the MiGs to Ukraine's pilots would be left to the...