Terrorism like 911 is almost certainly blow-back from America's entanglements in the Mideast, and not just entanglement with Israel (I suspect America's entanglement with Saudi Arabia is primarily what led to 911).
Had we listened to George Washington, I believe we most likely would not have been attacked.
Of course, we live in an increasingly shrinking world--and so I believe that Mr. Washington's admonition is more difficult to follow today.
But Mr. Washington did not say to avoid foreign entanglements altogether--he simply advised us to be wary.
Doubtless Mr. Washington was being mindful that foreign entanglements can lead to unforeseen dangers of bewildering complexity (I note his use of the word, "entanglements," instead of "alliances"), and so they are best avoided unless absolutely necessary.
Which means there must be some very convincing reasons for getting involved to begin with.