Why Europe stands to be hit harder than the US; and the UK harder than Europe.
While many factors influence the evolution of GDP, currently the prices of food and of energy are dominating: And here there are fundamental country differences.
The US is self-sufficient in the production of both. Hence, while US consumers of food and energy suffer a reduction in real income, US producers enjoy a commensurate increase. i.e. while the money gets moved around, it stays in the US.
Europe, however, while self-sufficient in food, is not in energy. Hence, part of its income loss is a gain to producers abroad.
The UK, being self-sufficient in neither, sees its income losses on both counts going abroad. Thus, however hard the US is hit, Europe stands to be hit harder; and the UK harder still.