Friday, a Russian SU-27 did a barrel roll over a U.S. RC-135 over the Baltic, the second time in two weeks. Also in April, the U.S. destroyer Donald Cook, off Russia’s Baltic enclave of Kaliningrad, was twice buzzed by Russian planes.  Vladimir Putin’s message: Keep your spy planes and ships a respectable distance away from us.

Apparently, we have not received it. Friday, Deputy Secretary of Defense Robert Work announced that 4,000 NATO troops, including two U.S. battalions, will be moved into Poland and the Baltic States, right on Russia’s border.

“The Russians have been doing a lot of snap exercises right up against the border with a lot of troops,” says Work, who calls this “extraordinarily provocative behavior.” But how are Russian troops deploying inside Russia “provocative,” while U.S. troops on Russia’s front porch are not? READ MORE