from your lips to god's ears

bit idea: dropping dozens of time-delayed firecrackers in the area

You reminded me of this scene from Wind River where local cops stand off with federally contracted security https://youtu.be/MK_edxQ5awc?si=t8zM1wD8ivqUXwf2

Very unlikely. For one, border patrol isn't big enough or well armed enough. They're cops, this will go to the courts.

Honestly? Whether you're a troublemaker or a foreign intelligence agency, just do some corny Tom Clancy shit. Forge documents that imply some kind of escalation (threats from the other side), then quietly distribute them to whichever side's more likely to attack first. Once the ball's rolling, it'd be hard to stop