It's an act of war.

[Queso Delicioso]

That's generally the case when one country starts killing another's citizens without provocation or any kind of due process. Venezuela would be well within their rights to retaliate. That doesn't have to mean open armed conflict, as that would almost certainly be a losing proposition for them, but they might decide it would be neat to host some Chinese or Russian bases. Or maybe they get a bunch of hackers on payroll and start fucking with US infrastructure. Trump wants to play like he's Billy Badass, but what he's really playing are the opening rounds of FAFO.