Its all fun until someone gets hurt.
Mexico has an obligation to protect people on their territory. They are not going to let us go in to “do” anything to these people.
Mexico also previously agreed to handle the problem with Trump. And they gave up. So it is now a pretext for a surgical operation. Mexico’s military is not a match for USA military.
Mexico has already surrendered any claim to soverignty by not acting to stop this invasion.