I didn't find Robert Kagan persuasive when he said that what Vladimir Putin, now Russian's prime minister, has to fear from NATO expansion into Ukraine and Georgia is only democracy, not a military threat ["Ideology's Rude Return," op-ed, May 2]. Mr. Kagan echoed President Bush on the subject in writing, "NATO is less provocative and threatening toward Moscow today than it was in [Mikhail] Gorbachev's time." ...