When Prime Minister Binyamin Netanyahu talks about the Iranian nuclear crisis, he frequently uses analogies drawn from World War II. But as he returns home to consider his next moves in light of what he heard from US President Barack Obama on Monday, I suspect he will be pondering events much closer in time and space: the experiences of his two immediate predecessors, Ariel Sharon and Ehud Olmert.It was on Sharon’s watch, as Ronen Bergman related in The New York Times in January, that Iran’s clandestine uranium enrichment operation at Natanz was first discovered, thanks to “cooperation between American, British and Israeli intelligence services.” Some Israeli officials wanted the site “bombed at once.” But Sharon opted for a different plan: “Instead, information about the site was leaked to a dissident Iranian group, the National Resistance Council, which announced that Iran was building a centrifuge installation at Natanz.” The outcome is well known: The news, quickly confirmed by International Atomic Energy inspectors, produced much talk but little action. Over the next 10 years, several rounds of sanctions were imposed, but these sanctions utterly failed to halt Iran’s nuclear program, which continued to progress apace. Since 2002, Tehran has produced enough low-enriched uranium for four nuclear bombs; further enriched some of this uranium to 20 percent, a step experts say is far more difficult to master than the subsequent stage of going from 20 to 90 percent (which is what is needed for a bomb); installed thousands of additional centrifuges, including at a new underground facility in Fordow that would be almost impossible to attack; and conducted experiments in weaponization, including technology to arm its missiles with nuclear warheads and “a highly sophisticated nuclear triggering technology that experts said could be used for only one purpose: setting off a nuclear weapon.”One can understand why Sharon decided as he did. Natanz was discovered at the height of the second intifada, when the army was fully occupied in combating the Palestinian terrorists who were slaughtering civilians in cities throughout Israel. Under these circumstances, the idea of opening a second front against Iran must have seemed daunting. But by not doing so, he allowed a relatively small problem to metastasize. Iran now has far more nuclear facilities, far better defenses, and above all, far more technological know-how than it did in 2002. Thus today, Iran’s nuclear program is both much harder to destroy and much easier to rebuild than it would have been when it was first discovered.This lesson wasn’t lost on Sharon’s successor, Ehud Olmert, when he faced a similar situation five years later: Israeli intelligence had confirmed that Syria was building a nuclear reactor, and that it was likely to become operational in another few months. Olmert first presented the evidence to then-President George W. Bush and asked him to bomb the reactor. But the Bush administration was divided: While Vice President Dick Cheney supported Olmert’s request, Defense Secretary Robert Gates and Secretary of State Condoleezza Rich preferred the diplomatic option – getting the IAEA to declare Syria in violation of the Nuclear Nonproliferation Treaty and asking the Security Council to impose sanctions. Ultimately, Bush sided with Gates and Rice: In his memoirs, he wrote that he proposed sending Rice to Israel immediately so she and Olmert could give a press conference disclosing the reactor’s existence.But to his great credit (and it’s one of the very few decisions he made as premier that I consider to his credit), Olmert rejected this proposal out of hand. It couldn’t have been an easy decision: Syria has thousands of missiles capable of striking anywhere in Israel, and chemical warheads to load them with; the threat of massive retaliation was very real. But he had seen firsthand, as a senior minister in Sharon’s government, how ineffective the diplomatic option proved with Iran, and he wasn’t prepared to let that failure be replicated on Israel’s northern border. Given the mischief a non-nuclear Syria was already making as the patron of anti-Israel terrorist organizations in both Lebanon and Gaza, the threat of a nuclear Syria – whose mischief-making potential would be vastly greater, because it would no longer be restrained by fear of provoking an Israeli attack on Damascus – was too deadly to be tolerated.The decision Netanyahu faces is incomparably harder. The chances of an attack on Iran being successful are unquestionably lower, given the much greater distances, the greater number of targets that must be struck, and Iran’s stronger defenses. It may well buy less time than the five years and counting bought by the Syrian strike, since the technological knowhow Iran has gained over the last 10 years will make rebuilding easier. The likelihood of retaliation is greater, because while the Syrian attack was a stealth operation that Damascus could and did decide to ignore, any attack on Iran will be the culmination of a very public confrontation, making it harder for Tehran to refrain from retaliation without losing face. And finally, while Olmert was confident that Bush, despite his initial opposition, would give Israel full backing after the fact (as indeed happened), Netanyahu can have no such confidence about Obama.But all these risks will have to be balanced against one inescapable fact: Sanctions and diplomacy have never yet succeeded in halting any country’s nuclear program. They didn’t succeed in North Korea, as detailed in a devastating blow-by-blow account in PJ Media last month; they didn’t succeed in Pakistan; and they aren’t succeeding in Iran – unless you define 10 years of steady progress toward nuclear weapons as “success.” In contrast, military action has succeeded the only two times it has been tried, in Iraq in 1981 and Syria in 2007: Neither country ever successfully reconstituted its nuclear program.I don’t know what decision Netanyahu will ultimately make, and I don’t envy him the responsibility of making it. But one thing I’m certain of: To persuade this very history-conscious prime minister to ignore the history of the last 10 years, Obama will have to come up with something a great deal more convincing than “trust me.” The writer is a journalist and commentator.