That's nonsense. The US was not involved in armed conflict from 1920 (end of involvement in the Russian Civil War) to 1941 (start of <edit: American involvement in> WWII). That's 21 years right there. Maybe they're saying that 21 years was the longest period between military conflicts.

> The US was not involved in armed conflict from 1920 (end of involvement in the Russian Civil War) to 1941

Except (among others):

1) The US intervention in the insurgency in Cuba (the "Sugar Intervention") which ran from 1917-1922.

2) The US intervention in China from about 1922-1927.

3) The use of the US military to clear the protesting "Bonus Army" of US veterans in Washington D.C. in 1932.

There may be 21 years without armed conflict by the US in its history, but they aren't 21 years in a row.

I think you're stretching the term "armed conflict" beyond any reasonable usage. Would you consider Indonesia to be engaged in "armed conflict" in Lebanon because they contribute troops to UN peacekeeping there (UNIFIL)?

The original commenter is trying to compare the number of years the US was involved in military conflicts vs. Europe. If you're going to include events as obscure as the sugar intervention (of which I found very little mention in books about Cuban history and US/Caribbean relations) then I doubt the comparison would be very meaningful.

UNIFIL isn't an intervention as (like in China where the intervention was to protect US, etc., imperial interest in Shanghai from groups directly targeting them) or on behalf of (as in Cuba, where the intervention was directly on behalf of the government against rebels) a principal belligerent, so I think the attempted analogy fails.

It was a relatively quiet patch in the warring , but a quick look at Wikipedia shows a fair few conflicts during that period including fighting internally against native Americans. Civil unrest with military action, landing troops to protect foreign interests which included shelling and shooting. It all depends how you define armed conflict. I'd say soldiers and guns = armed conflict. Others would say that a declaration of war was required. Have a look at this Wikipedia list of military actions - it may not be outright war, but it wasn't peace. http://en.m.wikipedia.org/wiki/Timeline_of_United_States_mil...

1941 was not the start of WWII. It started in 1939.

Not if you're Chinese, or Abyssinian.

The conflicts that became WWII started at different times in different places.

Yes, but the question is how many years has the United States not been at war. The US did not enter WWII until 1941.