After World War 2 the US (and West in general) supported its former enemies. Rebuilding cities, legal systems, and economies on a massive scale. Germany and Japan were the primary beneficiaries of that financial aid and guidance and today those two countries are large stable entities that improve the West’s standard of living by providing both solid trading partners and political allies.
Some argue that those countries now take “our” jobs when in fact the evidence is clear that those countries have expanded the global economy for all. It is true that the US, Canada and the UK have a smaller slice of the global economic pie in 2018 compared to1950, but the pie is many times larger, so the net benefit to those countries is irrefutable.
The rebuilding (not reconstruction) plan was named after then US Secretary of State George Marshall. Today the Marshall Plan is touted as the cure all for every failing state, from Afghanistan to Mozambique but, as this New Yorker article explains, for a Marshal Plan had a lot more to do with reassurance and a lot less to do with money than most people think.