At the time, Russia vowed to respond with retaliatory sanctions against U.S. officials. “Reciprocal steps from the Russian side will definitely follow,” said a Russian Embassy spokesman in Washington. When asked on Tuesday which officials will be targeted, the official told Foreign Policy he would send along details as they arrive and followed that message with a smiley face emoticon.

The severity of new U.S. sanctions against Moscow remains unclear as well. One of the most powerful weapons the West could use against Russia would be to target the country’s energy powerhouses, especially Gazprom and Rosneft. The two companies dominate Russia’s energy production and exports, and are the key levers by which Putin wields energy as a geopolitical weapon.

Bringing the hurt to the energy firms would deal a blow to an economy that is increasingly in trouble — both now and in the future. Oil and gas exports make up about half of Russia’s federal budget now.