HOUSE OVERSIGHT 018209 mysterious explosions like the massive blast at a missile base, which destroyed ballistic missiles that could reach Israel. The covert onslaught dovetails with Israel's history of reaching "over the horizon" to disarm perceived threats at a distance. To keep advanced arms from reaching Hamas and Hizballah, Israel in the past year sent warplanes to bomb convoys and arms depots in Sudan and Syria, respectively, without apparent retribution. In the case of Iran, however, experts say the audacity of Israel's covert campaign stirred Tehran to revive an espionage effort that lay largely fallow since 9/11. The Spy vs. Spy contest that ensued would prove woefully one-sided, even in the third-world countries where Iran chose to strike, hoping to avoid heightened security awareness in the developed world. In the end, its only success came inside Iran, where the secret police operate without inhibition. The shadow war may have started on Jan. 15, 2007, the day Ardeshir Hosseinpour passed away. Hosseinpour was a specialist in electromagnetics at the Nuclear Technology Center in the city of Isfahan, Iran, but his death might have escaped notice had Iran's government not kept it under wraps for almost a week, finally attributing it to fumes from a faulty heater. An online report by the American private intelligence firm Stratfor suggested another cause — radioactive poisoning — and hinted that Mossad's Caesarea section was back in business. Caesarea, named for an Israeli beach town that dates back to Roman times, is the operations branch of Israel's secret service, most notoriously responsible for the assassinations of some two dozen Palestinians (and an innocent waiter) after the 1972 Munich Olympics. Assassinations are carried out by a very small unit dubbed Kidon, the Hebrew word for "tip of the spear." Kidon operates at a remove from the legions of Mossad employees working in less lethal fields. It would have been a unit cal