Textron Systems NGSW Rifle and LMG

[Double Naught Spy]

Is it still considered an invasion if they are invited in to help “keep the peace” in a post-civil war landscape?

That would depend on whether you were on the side of civil unrest requesting the help or on the side not requesting the help.

Heck, there were people upset that we allowed Mexican military into the US to aid in hurricane relief after Katrina and Rita, 'foreign forces' on our soil and all that.