Well, no, actually they would come after us in several ways: uncontrolled illegal immigration, uncontrolled terrorist infiltration, and so forth. Terrorism is far more dangerous when it is state-sponsored. One of the things we have been trying to do is to end that kind of state sponsorship and support of terrorists.
Cogent words, indeed. State sponsored terrorism is a very nasty business. It is addressed in the constitution under 'offenses against the law of nations' and it is constitutional to 'punish' these offenses.
Many governments are guilty, including Russia, China, Iran, and Saddam's Iraq.
How to go about punishing these offenses is left to congress but these days it is the president who everyone looks to.
Of course, the constitution says 'punish', not invade and occupy.