The images flashing across our television screens, phones and tablets have been striking: Russian tanks, armored vehicles and helicopters crossing the borders into Ukraine to oust the democratically elected government and reassert Russia’s control over its former Soviet brother.

But one of the most-feared militaries in the world stalled in the face of fierce opposition from the Ukrainian military and civilians. Sympathetic but unable to intervene militarily for fear of escalating the conflict to a third world war, the U.S. government, in tandem with European allies, opted to impose economic sanctions on Russia, some of its leaders and select super-wealthy oligarchs who support President Vladimir Putin.