WASHINGTON, Aug. 5 (JTA) — When U.S. immigration agents caught Ghazi Ibrahim Abu Maizar illegally crossing the Canadian-American border earlier this year, he pleaded for political asylum. Israel had falsely accused him of belonging to Hamas and tortured him, Abu Maizar told authorities. A judge freed him on bail. No one checked out Abu Maizar’s story, and he later dropped his request for political asylum. That’s when the judge told the 23-year-old Palestinian laborer from Hebron that he had 60 days to leave the country. But Abu Maizar never got to leave. Just weeks before the judge’s Aug. 23 deadline, Abu Maizar was shot in his Brooklyn apartment when he lunged to detonate a bomb during a police raid. According to police, the bomb was intended for a nearby subway station. Last week’s arrest of Abu Maizar and Lafi Khalil, 22, — equipped with at least two active suicide bombs in their apartment — is believed to have averted a potential disaster. But the raid has raised some troubling questions: How did the federal immigration system allow the would-be terrorist to stay in the country without investigating his alleged background? Do other terror cells lurk behind closed doors in other American cities. As New York police, the FBI and Israeli agents cooperate in investigating the Brooklyn case, authorities have once again focused on the burgeoning militant Islamic movement in the United States. No one yet has established whether the two arrested men were operating alone or were connected with any Middle East terrorist groups. Hamas, which claimed credit for last week’s double suicide bombing in Jerusalem, has denied any involvement with those arrested in Brooklyn. But for terrorism expert Steven Emerson, an official link will probably never be found. “The search for the missing connection to Hamas central will not be found,” said Emerson, an investigative journalist who is finishing a book on militant Islamic networks in the United States. “The politics of militant Islam knows no boundaries. They are amorphous self-activated cells,” Emerson said in a telephone interview from Israel where he is on a fact-finding mission for a documentary series on international terrorism. CIA Director George Tenet testified in Congress earlier this year that terrorists, including militant Islamic groups, have expanded their activities and support networks in the United States. FBI officials say Hamas, Islamic Jihad and Hezbollah all have the capability and infrastructure to launch attacks in the United States. After the 1993 World Trade Center bombing, law enforcement agencies realized that the United States had become a target for international terror. Coincidentally, the alleged mastermind of that bombing, Ramzi Yousef, went on trial in New York this week. But four years after the World Trade Center explosion, the discovery of a suicide bomb cell in New York City revived those fears. “We haven’t really come that far from the World Trade Center bombing,” said Abraham Foxman, national director of the Anti-Defamation League. “One would have hoped that we would have taken care of such basics as screening terrorists at the borders,” Foxman said, calling the decision to let Abu Maizar stay for 60 days “a joke.” Foxman echoed the views of many when he called for a “100 percent U.S. effort against terrorists in the United States.” Hamas and other militant Islamic groups have secured a strong foothold in the United States, and their support continues to rise. Hamas alone has raised tens of millions of dollars in the United States, according to law enforcement officials and counterterrorism experts. One of the most celebrated cases of Hamas activity is that of Mousa Mohammed Abu Marzook, who served as the “foreign minister” of Hamas, allegedly raising hundreds of thousands of dollars from his northern Virginia home. Although U.S. officials arrested Marzook, who is a U.S. citizen, he was freed earlier this year when Israel dropped its extradition request, citing fears of Palestinian violence. In addition to arresting Marzook, there has been other law enforcement activity against Islamic militants: * The U.S. Customs Service is investigating a network of Islamic foundations, including the Florida-based World and Islam Studies Enterprise, which had close ties to Ramadan Abdallah Shallah before he left Tampa for Syria to take over the leadership of Islamic Jihad. * A leader of the International Institute of Islamic Thought was deported earlier this year as a suspected leader of Islamic Jihad. * Numerous cases are pending against Palestinian merchants accused of coupon fraud and money laundering. Police say they may have transferred millions to Middle East terrorism groups. As law enforcement agencies step up their investigation into militant Islamic groups, pressure is mounting on the Clinton administration to follow up its own counterterrorism efforts. Even before last week’s arrest, the Jewish Council on Public Affairs, an umbrella organization of Jewish community groups, planned to convene a conference call to discuss holes in the U.S. counterterrorism effort. Most notable, Jewish activists argue, is the State Department’s refusal to publish a list of overseas terrorist groups. Last year’s anti-terrorism law required such a list to enable law enforcement authorities to move against their fund raisers in the United States. “Money that is collected for charitable purposes is diverted for military and terrorist activities,” Philip Wilcox, director of counterterrorism at the State Department, told lawmakers earlier this year. Last month, 42 members of Congress urged the administration to act on the list. In the wake of the Brooklyn arrests, activists say they have new ammunition in the campaign to win approval for such a list. At the same time, many hope that the debate about Hamas’ dual roles as a humanitarian institution and a terrorist group will end. Hamas runs scores of clinics, hospitals schools, soccer leagues and mosques in the West Bank and Gaza. “You can’t look at Hamas in a vacuum. Kindergartens teach young children the ideology of Hamas: then it’s only a matter of time before Muslims will rise up and kill all Jews,” said Yehudit Barsky, a senior Middle East research analyst at the ADL who has written extensively on Muslim extremists in the United States.