Did the sanctions stop another invasion?

Ever since John Kerry's meetings in Sochi on May 12 with Vladimir Putin and Sergei Lavrov, the State Department has tried persistently to play down the idea of détente between the U.S. and Russia. As one journalist put it, Kerry was almost effusive in his thanks to Putin for hosting the talks, but State Dept. spokesmen nevertheless insist that the level of dialogue remains the same. In Prague, U.S. Amb. Andrew Schapiro gave his first post-Sochi interview to Deník. He wasn't asked about Kerry's meetings, but his remarks might nevertheless provide a clue about how the U.S. could try to justify turning away from Ukraine in the interest of deals on Iran and Syria. The sanctions have given Ukraine a chance to survive, Schapiro said, and have affected the Kremlin's calculations about whether it would pay to go further. So, the sanctions have stopped Russia from invading other countries? It's a bold claim, but many Czechs would buy it.