memes

Yes WW2 started in 1939, and Pearl Harbor was in december 1941. So it took 2 years for USA to get involved. But USA was such a massive influence, because their industrial output was without comparison bigger than anything else in the world. It was bigger than Europe combined. USA was also a major factor in keeping the trans Atlantic traffic open, and defeating the German submarines. D-Day would have been impossible without USA, as USA was the biggest force. USA also suffered the most losses in operation overlord, with almost twice the casualties and killed as UK. All that is apart from doing by far the most in the effort against Japan.

https://en.wikipedia.org/wiki/Operation_Overlord

It's denigrating to the American effort to call that waltzing in.

If it wasn’t for the supply shipments to Britain, they likely would have lost before things got close in the first place. Note it wasn’t just weapons but also food and medical supplies.

Edit: Also, the shipments were regularly attacked by German U-boats, so there absolutely was risk to American lives still.

America did play a rather isolationist position prior to pearl harbor.

Britain did play a rather isolationist position prior to the invasion of Poland. It's just a feature of diplomacy to avoid armed conflict at all costs. Kind of like when Britain secured "peace for our time" by offering Czechoslovakia to Hitler as a Sacrificial Lamb..

they didn't actively put boots on the ground until shit got really close.

False comparison. There was no alternative to "boots on the ground" for the European Allies when the war happened in their backyard, but there was certainly an alternative to the U.S. offering a quarter-trillion dollars (adjusted) in aid to Europe.

The US Merchant Marines were sinking German U-boats nearly a year before the US declared war.

Yeah they wanted the UK to give it all its patents first. They got paid off.