Is the U.S. Ready for a Russian Invasion of Eastern Europe?

The Baltic nations of Latvia, Lithuania, and Estonia, along with Poland, Slovakia, Romania, and Bulgaria, are all watching Vladimir Putin’s military buildup in eastern Europe with great unease. Each of them was controlled by Russia during its previous incarnation as the Soviet Union, and none of them wishes to return to that subjugation. That’s why they originally sought membership in the North Atlantic Treaty Organization, and have increased their own defense spending to meet, and in some cases surpass, the 2-percent-of-GDP goal that the alliance first agreed upon in 2014. NATO membership brings with it the guarantee...