Name one nation whose territory American has annexed. Just one.
The Mexican Republic—seized 1/3 of their nation. The Cherokee Nation took good lands and gave them deserts, killing lots of folks in the Trail of Tears. The Hawaiian Kingdom, stole the whole thing. The Kingdom of Spain, took Guam and The Philippine Islands as well as Puerto Rico. Lots of Pacific Islands from Japan to use as bases after WW II.
The Japanese territory where we still have bases is under the jurisdiction of Japan, is it not? We didn't annex anything into U.S. jurisdiction that I am aware of.
Texas fought a war for independence from Mexico before becoming a state....voluntarily.
Does Guam want independence? Does California desire to be "re-united" with Mexico? I don't think so. (OK, there are the La Raza racists, but nobody takes them seriously.) Yet EVERY eastern European country that was ever under the Tsarist and subsequently the Soviet yoke is fiercely defending the freedom from Russian tyranny that they gained 1991.
Moscow seriously claims the Ukraine is "Russian" despite having a different language, a different Orthodox Church, etc. Moscow is enforcing Russian civil law and Russian citizenship on the Ukrainian territory occupied in 2014, announcing to all and sundry that the occupied territory is now Russia, and is deporting ethnic Ukrainians wholesale.
Now THAT is annexation.
I notice that you believe the law of conquest was a good thing until the U.S. started conquering. Let’s look at the case of Mexico, which you treat as legitimate until it was defeated by the United States.
A few dozen conquistadors conquered Mexico because the conquistadors allied themselves with the subjugated tribes to overthrow their ruthless rulers.
The consequent territory was ruled by Spain as New Spain. During the Spanish period, there were incessant uprisings and intrigues. Finally, Mexico gained its independence from Spain in a long war of independence.
The consequent Mexican period was also one of incessant uprisings and intrigues. The central government of Mexico was constantly suppressing or trying but failing to suppress independence movements. Among these independence movements was one in the Mexican state of Texas.
The Texians (as they called themselves) flew the Mexican flag over the Alamo, with the number 1824 on it. They were demanding their rights under the Mexican Constitution of that year. But, not having their rights respected, they declared independence and won their independence in a short but decisive war.
When the consequent Republic of Texas joined the U.S. as a state, we thought there was some uncertainty about its border with Mexico. Was it the Rio Grande or the Rio Nueces? President Polk sent an envoy to Mexico to try to resolve the matter, with an offer of $5 million to put the border at the Rio Grande.
But, no, the flamboyant general and sometimes dictator of Mexico, Santa Ana, was going to defend every inch of Mexican territory to the Sabine River (the border of Texas with Louisiana). And, so, we got into a war with Mexico.
At what point did the right of conquest turn bad? When the U.S. defeated Mexico? Or, was it always bad? Isn’t the sorry history of mankind one of one war after another? The question shouldn’t be who has the right to be anybody’s master, because nobody has that right. Rather, the question should be when will everybody be free?
We’ve been trying for about a hundred years now to end war as a means of national policy. Obviously, we’ve not been successful. Our failure to end war doesn’t justify Russia’s invasion of Ukraine. It means we must be vigilant in our own defense, and it means that small and medium-sized nations should consider joining into mutual defense with others to secure their independence.