Should Israel be classified as a state sponsor of terrorism? That question is being debated in the wake of a story that NBC News broke late last week.

Citing unnamed US officials, NBC reported that Israel has used an Iranian opposition group to carry out those much-publicized assassinations of Iranian scientists. The group in question is the M.E.K. (Mojahedin-e Khalq, or People's Mujahedin of Iran), which since 1997 has been designated a terrorist group by the United States because of its alleged assassinations of US citizens.

The argument for considering Israel a supporter of terrorism comes in two varieties:

1) According to NBC, Israel gives the M.E.K. the funding, training, and weapons to carry out the assassinations--and that would seem to constitute support for a terrorist group.

2) Leaving aside the M.E.K. involvement, there's the argument that the assassinations inherently constitute terrorism. Andrew Sullivan and Kevin Drum had previously suggested that whoever is behind the assassinations is committing terrorism, but this NBC story is the first mainstream media corroboration of the widespread suspicion that Israel is behind them.

After the NBC story broke, Paul Pillar, a former CIA official who teaches at Georgetown, dusted off the definition of terrorism used by the US government for purposes of keeping statistics: "premeditated, politically motivated violence perpetrated against non-combatant targets by subnational groups or clandestine agents." That, says Pillar, is what these assassinations are.

The counter-arguments have tended not to be big on legalisms. There is the "Look who's talking" argument. "Isn't Iran itself the leading exporter of terrorism in the world?" asks The New York Post. And there's the argument that Iran is an existential threat to Israel and therefore all is fair. "Israel is entirely justified in using whatever means it has to prevent Khameini's government from achieving its genocidal ends," writes Jonathan Tobin in Commentary.

Daniel Larison, writing in The American Conservative, was aghast at Tobin's argument: "In other words, Israeli state sponsorship of a terrorist group is acceptable because it's in a good cause."

This whole issue is in one sense moot. Adding a country to the list of states that sponsor terrorism requires executive branch initiative. And unless I'm misreading the political winds, placing Israel alongside Iran as a state sponsor of terrorism isn't high on President Obama's list of election-year priorities.What's more, strict and consistent enforcement of America's anti-terrorism laws could raise uncomfortable questions about some of America's drone strikes.

Still, there may be some consequential fallout.

There has been a movement afoot to "de-list" the M.E.K.--to remove it from America's list of terrorist groups on the grounds that it has renounced violence and, anyway, hasn't killed an American in a long time. This argument gets made mainly by Americans who support bombing Iran or even engineering regime change--a project the M.E.K. would love to abet. (A few other high-profile Americans have signed on to the de-list-the-M.E.K. cause, but as The Christian Science Monitor reported, they have shown a tendency to get paid tens of thousands of dollars for the speeches in which they express their newfound yet heartfelt sympathy for the M.E.K.)

As Glenn Greenwald wrote in Salon, the NBC report should, if nothing else, "completely gut the effort to remove the M.E.K. from the list of designated terrorist groups; after all, murdering Iran's scientists through the use of bombs and guns is a defining act of a terror group, at least as U.S. law attempts to define the term."