The most worrying aspect of the recent string of Iranian terror attacks in Asia was the evident drive to commit them even though they hadn't been properly prepared. The three attacks in New Delhi, Tbilisi and Bangkok did no more than wound one Israeli diplomat's wife. No Israelis were killed, and no high-quality target (like an embassy, passenger plane or official delegation ) was hit.

Those who sent the terrorists could have predicted that the results wouldn't justify the investment, and that compared to the assassinations of key Hezbollah operative Imad Mughniyeh four years ago and of several Iranian nuclear scientists in recent months - all of which Tehran attributes to Israel - Iran would still end up behind in this bloody competition. And yet, it nevertheless rushed into action.

Such haste is not typical of Tehran's previous decision-making, and it shows that the decision makers are under pressure and liable to be driven more by emotions than by cool calculation. This may foretell escalation as well as a weakening of the restraints that have slowed progress on Iran's military nuclear program.

The working assumption of Western intelligence services is that Iran has been secretly deploying its forces so it could retaliate against American and Israeli targets. Iran could potentially gain by using these forces to create deterrence, but it's not worth acting for only limited effect: Scattering hints would be enough.

Like Hezbollah's cross-border kidnappings on July 12, 2006, it seems the recent attacks in Asia may have been a premature error. Israel's response to the former - the Second Lebanon War - dealt Iran a severe blow, by destroying much of Hezbollah's rocket arsenal (which has since been restored ) and changing Hezbollah's calculations regarding another round. This week's attacks risked antagonizing India, which has been Iran's lifeline from the tightening noose of economic sanctions; they will deepen Iran's diplomatic isolation; and they will spark efforts to uncover other Iranian agents stationed for use in emergencies. These are serious costs that domestic considerations (power struggles within Iran's ruling clique, the upcoming parliamentary elections, growing economic distress ) might explain, but certainly do not justify.

Moreover, from Iran's standpoint, Israel isn't a principal front. Iran has been actively engaged in fighting American and allied forces in Iraq and Afghanistan, and is now rushing to the aid of its embattled Syrian ally, President Bashar Assad. On the Israeli front, it has focused mainly on arming Hamas and Islamic Jihad. Thus the people available to carry out the attacks in India, Georgia and Thailand were probably not the star graduates of its sabotage courses.

But this week's failures don't mean the next Iranian attacks won't succeed - because Israeli intelligence also failed. Israeli agencies missed both the preparations for the attacks and the decision to carry them out simultaneously in several countries.

Iran's terrorist infrastructure spans the globe and enjoys all the advantages reserved for a state: embassies, diplomatic passports, secure communications, diplomatic mailbags (via which weapons and explosives can be smuggled into the target country, avoiding the risk involved in securing them locally ), and diplomatic immunity for its staff, cars and houses. The Revolutionary Guards' Quds Force and the Intelligence and Security Ministry - the two bodies responsible for overseas attacks - both have representatives on Iranian embassy staffs.

The weakness of this diplomatic network is that it can be monitored, including through attempts to intercept embassy communications with Tehran. To evade such monitoring, Iran has sometimes preferred to bypass its local embassy and send in terrorist cells for one-time operations. This can involve aid from local sleeper cells, or from supporters among local Iranians, Lebanese or other Shi'ites.

An instructive example, despite its failure, was last year's amateurish attempt to assassinate the Saudi ambassador in Washington: An Iranian-American citizen contacted someone in Mexico City known to have connections with a Mexican drug cartel in order to hire cartel assassins to carry out the plot. The plan fell through because the Mexican contact turned out to be an undercover American agent.

U.S. Attorney General Eric Holder later announced that the attack was ordered by the highest levels in Tehran. Two weeks ago, U.S. Director of National Intelligence James Clapper said explicitly that Iran's supreme leader, Ali Khamenei, was suspected in the plot.

Clapper's annual intelligence assessment said that Khamenei and his colleagues "are now more willing to conduct an attack in the United States in response to real or perceived U.S. actions that threaten the regime." Such attacks could also take place overseas, Clapper warned, against either American targets or American allies.

Iran's willingness to undertake such attacks depends both on what they cost and on the degree to which the regime feels threatened. Clapper may be right in stating that Iran is motivated by cost-benefit calculations, but the costs and benefits are measured in Iranian terms, not American ones. Therefore, it is premature to say that logic dictates Iranian restraint until the threat is truly imminent.

And what about Tuesday's decision by the Israel Police to raise the alert level nationwide and have all units immediately review the rules of engagement? Did the Revolutionary Guards somehow sneak a cell into Israel?

Like the Iranian attacks, the Israeli panic is a bit premature. The police would do better to save it for later: It may yet come in handy someday.