Like the USA and Mexico?

but I agree with you, except when it comes to tough decisions like making the USA bigger than it was prior to US/Mexican war
It always amazes me that people do not realize there were 2 separate wars between Mexico and Texas.
The first was in 1836, and did not really involve the US at all. That is when Texas revolted from Mexico, and became the Republic of Texas.
Texas at that time became an independent nation, until 1845 when at the request of the people of Texas they petitioned and became the 29th state, almost a decade after becoming independent.
Now by this time General Santa Anna had been deposed, and returned to power. He refused to recognize the treaty that granted Texas it's independence, and insisted it was all still Mexican territory.
A year after annexation, a company of US Dragoons was ambushed near Brownsville, Texas by a heavy brigade of Mexican forces. 16 were killed, 5 were wounded, 49 were taken prisoner, and 1 escaped.
This is the incident that started the Mexican-American War. And during the course of this war, California had it's own revolt and joined the US as well.