Palin on border patrol

Okay, it's shooting fish in a barrel to point out absurdities in Sarah Palin's foreign policy gyrations (this moment with Katie Couric has to be seen to be believed -- think Diane Keaton in Annie Hall). Still, a Palin comment at Ground Zero in New York today, reported by the AP, deserves to be parsed:

Palin was asked if she thought the U.S. presence in Iraq and Afghanistan was helping to mitigate terrorism

"I think our presence in Iraq and Afghanistan will lead to further security for our nation. We can never again let them onto our soil," she said.

Barreled fish, hold still:
1) How does our presence in Iraq and Afghanistan keep "them" off our soil?
2) Who exactly are "they"? Iraqis? Afghanis? The 9/11 terrorists, who hailed mainly from Saudi Arabia?