WASHINGTON (AP) — Underlying the talk about taking harsh punitive measures against Russia for its military incursion into Ukraine are economic complications and worries that sanctions levied against Moscow could, in the words of the Kremlin, “boomerang” back on the U.S. and Europe.

Heavier U.S. and European Union sanctions could sting Russia’s already slow-growing economy and hurt its financial sector. But Moscow could retaliate and seize American and other foreign assets or cut exports of natural gas to Europe, which is heavily dependent on Russia for energy.