Prime Minister Benjamin Netanyahu declared yesterday that the Burgas terror act was perpetrated by Hezbollah, which he tied to Tehran. This was quite a shift from his position Wednesday, when he hurried - in his public statement and in conversation with U.S. President Barack Obama - to pin the blame on Iran. Obama preferred to suspend accusations until the investigation is complete.

The painful murder of seven people, including five Israelis, and the wounding of dozens more, remind us all how exposed the entire world is to terrorism. No place, be it crowded or desolate, is immune. With a meticulous search for an opportunity, methodical planning and clandestine preparations any target can be attacked; and even if the attack fails time after time, in the end it will succeed in a different time or place.

That is the case when the plotter is a terrorist organization, which has no solid base and no systems that be placed under surveillance, and even more so when the adversary is a hostile regime like the one in Tehran. Powerful forces in Iran, particularly the ministries of intelligence and defense and the Quds Force paramilitary arm of the Revolutionary Guards, are working tirelessly to strike at Israel themselves, and through proxies in Lebanese, Palestinian and other groups. It would not be surprising if there is something to the accusations Netanyahu made.

But especially when the suspicion is backed up by facts, it is surprising how Netanyahu knew, two hours after the attack and obviously based on the intelligence services at his disposal, what those same services, and therefore he as well, did not know before the attack - which would have allowed it to be thwarted. This point should be investigated so its lessons can be learned and so as not to further erode Netanyahu's dubious credibility. Israel's part (reports of which were never officially acknowledged ) in the attacks that struck scientists in Iran should also be investigated; and whether such participation was properly analyzed in terms of cost and benefit.

Despite the pain and the anger, Israel must not repeat the mistake that led it to launch two wars (in Lebanon) following terror attacks. The issue of dealing with the Iranian nuclear program must not be influenced by the attack in Burgas.