Which U.S.-based terrorist groups or individuals performing acts of terror overseas are you referring to (any citations or examples)?

None were named in the entire article although extremely relevant to your expressed argument/opinion... why?

I'm just not aware of any foreign countries actively complaining of actual U.S. terrorists/citizens/paramilitaries uncontrollably crossing out of the U.S. to attack their citizens with any frequency or organization. Which is what your solution would seek to prevent; but would in reality actually just be a wasted, non-useful effort from a risk management perspective as well as the perspective of other governments and people.

Mr.Pillar is correct in as far as this article remonstrates. However, Mr. Pillar fails to note that both the United States and its European allies have been exporting terrorism (religious and economic) for centuries, and continue to do so. Sharing information and stopping United States except-us-ism while attempting to police foreign populations and control and consume the worlds resources will do nothing to halt the ever escalating levels of hatred and violence confronting all of us. If the western world truly wants to stop terrorism, it will have to stop exporting terrorism.

In this article: "It cites the example of Italy issuing criminal warrants in 2005 for the arrest of U.S. officials involved in the abduction and rendering to Egypt of an Egyptian cleric. Again, think of the roles being reversed: It would be a subject of great outrage, to put it mildly, in the United States if Italian officers were found to have secretly abducted someone from U.S. soil and flown him out to be locked up in someone else's prison. "

The abduction and rendition in Italy was helped by Italian intelligence agents, some of whom were also charged by the prosecutor in the case, but most were acquitted or had their charges dropped, while most of the American CIA officers were convicted, and therefore can't ever return to Italy. The Italian government tried to get the prosecutor and the judge to drop the case, but they refused.

"Think about what the U.S. reaction would be if, say, France claimed jurisdiction over a terrorist crime that a U.S. citizen committed on American soil, in which a visiting Frenchman happened to be one of the casualties."

This is precisely what's happening between France and Rwanda regarding the downing of Habyarimana's plane in 1994, in which a handful of French nationals were on board.

Pillar's statement about the resulting legal chaos is correct -- it raises questions about the viability of claims to universal jurisdiction, and even tangentially, the long-term viability of institutions like the International Criminal Court.

"They are expected to do whatever it takes to prevent their citizens from committing terrorist acts abroad, with little American patience for excuses about how difficult it is to control borders or the activities of private individuals."

We are not talking so much about the supervision of private individuals as asking for a willingness to go after known terrorist organizations. Pakistani military support for terrorists crossing into Kashmir and the recent deal in FATA to leave terrorists alone as long as they only attack in Afghanistan are unacceptable.

"It would be a subject of great outrage, to put it mildly, in the United States if Italian officers were found to have secretly abducted someone from U.S. soil and flown him out to be locked up in someone else's prison."

This type of case, in which government officials act for their governments in their official capacities are foreign relations cases to be negotiated between the respective governments, not matters for the individual officers to be tried in foreign courts of law.