70 years ago.

[McClef]

The American perception in 1939 was that it was primarily a European War (though the British Empire was also involved) so I expect that Pearl Harbour was the defining moment for US entry and still is in how history is viewed.

Sympathies were growing in the intervening period however including practical help such as Lend Lease.

[davedove]

Sympathies were growing in the intervening period however including practical help such as Lend Lease.

As well as the many US pilots who flew and died for the British.

[macwilkin]

As well as the many US pilots who flew and died for the British.

As well as a number of Americans serving with Canadian forces, the French Foreign Legion, etc.

T.

[KFCarter]

As well as a number of Americans serving with Canadian forces, the French Foreign Legion, etc.

T.

And more than a few Americans who served and fought in Asia long before Pearl Harbor.