The limited leverage of a Cold War blockade of the Soviet Union

Did Cold War planners intend to blockade Soviet merchant shipping, and would it have defeated the USSR?

Merchant shipping would be swept up, but a blockade alone was unlikely to decide the war; land combat and industrial sustainment were more important.

Soviet merchant shipping abroad could be seized quickly, but the USSR's continental scale made blockade less decisive than it would be against a maritime-dependent state. The quality of coal, fuel, and industrial inputs could be more troublesome than simple access to food. A conventional war would likely encounter ammunition and artillery-tube constraints within months on both sides. Mobilizing lower-readiness Soviet armies would deepen the maintenance problem because their older artillery required more relining and repair.