What to know about the West's new efforts to slash Russia's oil revenue

An oil tanker is moored at the Sheskharis complex, part of Chernomortransneft JSC, a subsidiary of Transneft PJSC, in Novorossiysk, Russia, Oct. 11, one of the largest facilities for oil and petroleum products in southern Russia. The deadline is looming for Western allies to agree on a price cap on Russia oil. (AP)

The United States and its allies are about to deliver a double blow to Russia aimed at starving its oil revenues.

First, the European Union will ban all seaborne imports of Russian oil, a move that takes effect Monday.