GAZA CITY, Gaza Strip - As leader of the militant group Islamic Jihad, Mohammed al-Hindi should have little to do these days.
A cease-fire between Palestinians and Israelis is in its second month, and all should be quiet. Hindi, a pediatrician by training, sits behind an oak desk, surrounded by leather-bound books on Islamic revolutions, but he is working on a checklist.
It's a list of what he says are Israeli violations of the American-backed cease-fire and peace plan - shootings, arrests, raids and the continued construction of a wall cutting through Palestinian villages in the West Bank.
These are transgressions, he says, that will doom the cease-fire, which is scheduled to expire at the end of next month. They "prove to the world that it is the Israelis who are the real terrorists," he says. And his own forces, he says, are preparing for renewed action - attacks that he would not otherwise describe.
Israeli security officials say that Hindi and leaders of other militant groups, such as Hamas, are taking advantage of army withdrawals to regroup, rearm and rebuild for what the officials ominously refer to as "the day after."
"We are taking a risk every day that is passing," a senior Israeli security source said this week at a briefing for reporters on the condition that he not be named. "It may just happen that the momentum of the cease-fire will lead us to a better world, and then the risk will have been worth it."
But if it doesn't, the official warned, "then we are in for a tsunami of terror."
Israeli officials say they are especially concerned by evidence that rogue members of the secular Aqsa Martyrs Brigades are receiving new financial support from Iran.
Each side assumes that the other is preparing for the worst.
"I don't think Hamas is collecting flowers for the day after," the Israeli security official said.
A Palestinian political analyst countered later: "I don't think the Israeli army has stopped cleaning its weapons."
Yesterday, the Israeli army killed two Hamas militants in a refugee camp near Nablus and blew up what it said was an explosives factory. One Israeli soldier was killed, along with another Palestinian. The army has vowed to continue making arrests in the Palestinian cities it still occupies, but a Hamas leader called the raid a "gross violation" of the cease-fire.
The truce is under strain from a variety of forces in Israel, the West Bank and Gaza. Israeli and Palestinian officials each portray their actions as monumental concessions while complaining about the inadequate steps taken by the other side.
American officials here have remained silent about their role as arbiters, though convoys of Chevrolet Suburbans with U.S. Consulate license plates are seen daily driving through Gaza. Palestinian police are out in force at checkpoints and searching cars for guns, but Israel complains that the increased actions are only cosmetic.
Palestinian police say they have prevented attacks against Israel, seized weapons, and closed tunnels used for gun smuggling at the border with Egypt. But they refuse to arrest militants or target their organizations. Hindi confirmed that no one in his group has been jailed, nor has he been asked to disarm.
"The Americans are here trying to build a strong Palestinian police force," Hindi said. "They are not doing this for traffic control. They want a force that will crack down on Palestinian factions. I don't think that is going to happen."
Hindi oversees the Gaza and West Bank membership of Islamic Jihad, a small faction that became active here in 1979 and advocates the destruction of Israel.
Hindi said he is convinced that the American peace plan will collapse and that the failure will convince even the Palestinian officials negotiating with Israel "to join the resistance movement."
The Israeli army maintains that militant groups are violating the spirit of the cease-fire by moving arms, holding meetings, sending "sleeper cells" into Israel and building an arsenal of rockets that could threaten Jerusalem and Tel Aviv.
But it is the alleged Iranian connection that has Israel's military establishment most concerned. The Hezbollah militia in southern Lebanon, backed by Iran, has long helped Palestinian militants by supplying arms and training.
Israeli officials say the evidence of Hezbollah's influence extends to Palestinians' improved fighting tactics, including well-planned ambushes and sniper attacks.
In January last year, Israel intercepted a ship carrying high-powered weaponry that officials said had come from Iran and was headed to the Palestinian Authority. Israeli officials said this week that they seized another ship last month off the coast of Cyprus, a vessel that sailed from Lebanon and carried video instructions for suicide bombers.
Israeli security officials say they have now have evidence that Iran gave financial support to members of the Aqsa Martyrs Brigades in the northern West Bank, and to an umbrella group in Gaza called the Popular Resistance Movement. They also say they have evidence linking 15 attacks in the past three years to Iran, actions that killed 50 Israelis.
Since the start of the cease-fire June 29, three Israeli civilians and a foreign worker have been killed in other actions that the army ties to small numbers of Iranian-backed militants.
"They want to sabotage the political process between Israel and the Palestinians," the Israeli security official said.
The official accused a charitable organization in Gaza called the Ansar Institute of funneling money from Iran to militant groups. He offered no evidence of the links and would not comment further.
The institute's office is in the center of Gaza, above a strip of stores that includes a beauty salon and a print shop. A sign outside says "Al-Ansar Benevolent Society."
The office's stairway and reception area are akin to an art gallery of posters showing Palestinian gunmen killed in the past three years. They share wall space with a framed portrait of Iran's spiritual leader, Ayatollah Ali Khamenei.
One of Al-Ansar's officials reluctantly agreed to an interview but refused to give his name. He talked of the group's work with orphans, the homeless and the destitute. It gives up to $200 a month to families of Palestinians killed in fighting or in attacks. The man said the organization was established three years ago with help from Iran.
"We give help to needy families, only, only, only," the man said, showing a colorful brochure and denying any support for militant activities.
A Palestinian political analyst in Gaza, Mohmoud A. Ajrami, said Iran sought to keep the Israeli-Palestinian conflict going to limit U.S. influence in the region, but he argued that Israel exaggerated Iran's role with Palestinian militant groups.
"Iran has never had an organized system related to helping the Palestinian resistance," Ajrami said. But, he warned, "Any cease-fire between enemies is serviced by both the hope for peace and the preparation for the next round. The militant groups have not gone to sleep."