Greater interdependence reduces the likelihood of conflict between nations or groups of nations by increasing the cost of conflict for all of them. However, as the EU-Russian case shows, the logic can also work in reverse. It is incredibly difficult to punish economic partners for international aggression.
In recent months, the United States and the EU have ratcheted up diplomatic and economic pressure on Russia in response to its activities in Crimea and eastern Ukraine. Although the United States has hit major Russian companies with significant sanctions, the EU has remained decidedly more hesitant. It took the downing of Malaysia Airlines flight MH17 on July 17, purportedly by Russian-supplied separatists, and Russia’s increased involvement in eastern Ukraine in the weeks thereafter, for the EU to even begin matching its threats with real action.