After years of counterinsurgency in the Middle East, the Pentagon says the biggest threat to U.S. security is Russia. That’s not just because of Russia’s nuclear weapons, it’s “hybrid warfare” of the sort Vladimir Putin is using in eastern Ukraine. U.S. troops are already training to combine counterinsurgency with conventional weapons, street-level fighting, cyber warfare, and propaganda. One very concrete example of that changing strategy took place in the Mojave Desert earlier this month in an exercise called Operation Dragon Spear. The goal is deterring Russia from moving on NATO members Latvia, Estonia, and Lithuania—or other members of the former Soviet Union.

Carnegie’s Dmitri Trenin talked to KCRW on this issue. Ryan Faith of the Vice News, Christopher Chivvis of the RAND Corporation, and Michal Baranowski of the German Marshall Fund were also featured, along with host Warren Olney.

Trenin’s key point was that Russia’s attitude toward Ukraine differs fundamentally from its view of the Baltic states and Poland: Ukraine is part of what Putin calls “the Russian world,” while the latter are seen as parts of the Soviet empire that are “lost forever.” There is no reason, therefore, to believe Putin will do to other countries what he has done in Ukraine.

Asked whether NATO’s attempt to shore up its eastern flank would be an effective deterrent toward Russia, Trenin suggested the question missed the mark, because a Russian attack on NATO’s eastern member states was never likely. While acknowledging that history had given eastern Europe reason to fear Russia, Trenin argued that it would be wiser to focus on the threat of escalation in eastern Ukraine—the potential for more direct Russian and NATO involvement in the fighting in Donbas is “a clear and present danger.”

This interview was originally broadcast on KCRW.