According to the Brennan Center for Justice, the President can invoke the act without a war declaration if a foreign government threatens or attempts an “invasion” or “predatory incursion” against US territory. Invasion in that context has historically been defined as large-scale attacks, while “predatory incursion” has been defined as small skirmishes. And it’s the latter that Trump is hinging his argument on by declaring that the gang he’s claiming to target is working on the orders of the Venezuelan government.
https://www.brennancenter.org/our-work/research-reports/alien-enemies-act-explained
Noita flashbacks… those damn frogs got me the first time I saw them because they looked so harmless!