Frankly, what was the difference between Germany, France and Britain then? None of them were saints. Why was it the US business? And don’t bring up the Zimmerman Note. Germany had no presence in the Americas, unlike Britain and France.
My grandfather who was in the Secret Service went to Mexico to investigate the situation regarding the Zimmerman letter. I would bet that were here alive today he would disagree with you.
it was our business because 1) German subs started sinking our ships - until then we were just providing munitions and supplies; and 2) Germany was actively encouraging Mexico to join the Central Powers and declare war on the US (they tried the same in ww2)