Do you know how the alleged "shopping-mall" bomber entered our country? He didn't cross the border illegally. He didn't sneak in on a ship. He came through the front door at America's invitation.

 Nuradin M. Abdi, who was indicted last week for plotting with al Qaeda to blow up an Ohio shopping mall, flew here from Somalia and received bogus "refugee" status in 1999, according to authorities. Prosecutors allege that Abdi then fraudulently obtained a refugee travel document, which he used to fly to Ethiopia for jihad training. After returning, Abdi blended back into the American landscape along with tens of thousands of other refugees from a country known to be a breeding ground for Islamic terrorists. Columbus, Abdi's home base, is home to more than 30,000 Somalis -- the second-largest Somali community in the United States, after Minneapolis.

 The Somali-al Qaeda connection is well-established. Intelligence reports indicate that Osama bin Laden sent extremists to Somalia in the early 1990s to train and organize the Somali Islamic radical group al-Ittihad al-Islamiya. Bin Laden claimed responsibility for the deaths of 18 American soldiers in Mogadishu. In addition, a Saudi Arabian-based Muslim charity with alleged ties to al Qaeda has been funding refugee camps in Somali border towns. The feds have frozen the Al-Haramain Foundation's assets based on terrorism grounds, but the flow of refugees from the overseas camps subsidized by the group has not been stanched.

 Not every Somalian refugee or asylum-seeker is a terrorist, of course. But the system for screening out the well-meaning from the menaces is completely overwhelmed. Claims of "credible fear of persecution" are almost impossible to document but are rarely rejected. Federal homeland security officials are unable to detain asylum-seekers for background checks without the civil liberties brigade screaming "racial profiling." And there is still a woeful shortage of detention space -- just 2,000 beds nationwide -- to hold those with suspect claims.

 As a result, thousands of refugees and asylum-seekers who have made flimsy claims of persecution are let loose. As the Department of Justice's inspector general reported, 97 percent of all asylum-seekers from any country who were released from immigration custody were never found again and deported.

 Abdi's case cannot be viewed in isolation. At least three other high-profile Islamic militants that we know of exploited the asylum system over the past decade:

 Ramzi Yousef landed at New York City's JFK airport from Pakistan and flashed an Iraqi passport without a visa to inspectors. He was briefly detained for illegal entry and fingerprinted, but was allowed to remain in the country after invoking the magic words "political asylum." The then-INS released him because it didn't have enough space in its detention facility. Yousef headed to Jersey City to plot the 1993 World Trade Center bombing.

 Gazi Ibrahim Abu Mezer, a Palestinian bomb-builder, entered the U.S. illegally through Canada in 1996 and 1997. He claimed political asylum based on alleged persecution by Israelis, was released on a reduced $5,000 bond posted by a man who was himself an illegal alien, and then skipped his asylum hearing after calling his attorney and lying about his whereabouts. In June 1997, after his lawyer withdrew Mezer's asylum claim, a federal immigration judge ordered Mezer to leave the country on a "voluntary departure order." Mezer ignored the useless piece of paper. He joined a New York City bombing plot before being arrested in July 1997 after a roommate tipped off local police.

 Mir Aimal Kansi, convicted in 1997 of capital murder and nine other charges stemming from his January 1993 shooting spree outside the CIA headquarters in McLean, Va., also exploited our insane asylum laxity. Despite his history as a known Pakistani militant who had participated in anti-American demonstrations abroad, Kansi received a business visa in 1991. After arrival, he claimed political asylum based on his ethnic minority status in Pakistan. While his asylum application was pending, he obtained a driver's license and an AK-47, murdered two CIA agents, and wounded three others.

 The feds deserve credit for tracking down asylum abusers suspected of terrorism. But homeland security would be easier to achieve if they did a better job of keeping murderous frauds out in the first place.