That’s a pretty bold assessment of Americans. You know who else thought that? Hitler.
And no, this isn’t merely invoking Godwin’s Law. The Axis powers immediately turned around and declared war on the US despite everything objectively pointing to it being a bad idea because they figured that our country could be defeated on the morale level first. They thought Americans were simply too materialistic, too individualistic, and too tired from the trials and tribulations of the Great Depression that they couldn’t stomach the sacrifices both on the frontlines and at home for a prolonged World War on two fronts. We proved them wrong.
Fast forward to the 1990s and the first Gulf War. Again, despite every objective analysis telling him otherwise, Saddam thought that all he had to do was draw the Americans into a “mother of all battles” and the sheer number volume of casualties would cause another large antiwar movement like in Vietnam and force the Americans to withdraw. We ended up smashing his country in under a year.
Yes, Americans do get war weary and impatient, but that has only applied to asymmetrical wars that drag on with no definite win condition that is easy to explain to the public. But when it comes to a conventional war against a clear enemy that is at least perceived as a negative force in world affairs, the idea that Americans can’t handle a war has proven to be BS twice already. What makes you think this will be correct the third time? You do know what the definition of insanity is, right?
Also, I find it funny that you use the Suisse power index to should that a combined Russia-China military alliance would defeat us, but ignore the other nations on that list that happen to be part of NATO or we have strong military ties with otherwise. Russia and China, may have a combined power index of 1.59 which does eclipse ours, but what the Hell makes you think our allies in Europe and the Pacific are just going to stay indoors and twiddle their thumbs while war wages in their own backyard? When you factor in the nations on that list that we have strong military ties with, that bumps our power index to 4.63. Almost three times as much as your theoretical Russo-Chinese alliance. And that’s on the assumption that Turkey and Taiwan would sit out the war for political reasons.
What I’m trying to say is that this reads increasingly like you got your geopolitical analysis from playing Call of Duty.