WASHINGTON – The successful mission against Osama bin Laden shows how far this country’s national security apparatus has come since 9/11, but the al-Qaida leader’s death doesn’t mean terrorist threats will disappear, U.S. Sen. Susan Collins said Monday.

Collins, the top Republican on the Senate Homeland Security Committee, held a Capitol Hill news conference along with U.S. Sen. Joe Lieberman, the committee’s chairman. They warned of the need for Americans to be on heightened alert for a potential act of retaliation, possibly by a “homegrown” terrorist.

“It is not the end of our fight against Islamic extremism,” said Collins, who learned of bin Laden’s death after receiving an urgent email Sunday night saying the White House was trying to reach her. “We must continue to not let down our guard and we must continue to be vigilant.”

On Monday, U.S. Sen. Olympia Snowe, R-Maine, recalled her 2008 trip to Afghanistan as a member of the Senate Select Committee on Intelligence, during which she met in remote outposts with the type of special military operatives who carried out the mission against bin Laden.

“These are amazing, remarkable, extraordinary individuals who do these heroic things every night while we are sleeping,” Snowe said. “This is a very clear message to our enemies. No matter how long it takes, no matter where you are, you can run but you can’t hide.”

Collins said that there can be no doubt it was bin Laden who was killed, though it may be necessary to produce photos, video or DNA evidence to “put to rest” any al-Qaida or terrorist sympathizers’ attempts to paint his death as a fabrication.

The decision to bury his body at sea was the correct call, she said, saying any known gravesite would merely provide a “source of inspiration to terrorists who would journey to the grave and view him as a martyr.”

Snowe agreed, saying she wouldn’t want a bin Laden gravesite to become an “area of veneration” for a group of people who are “our true enemies.”

Snowe said Americans will continue to live in a post-9/11 “new normal” where they must always be watchful and on guard against a terrorist attack on U.S. soil — but even more so in the days after bin Laden’s death.

“There is always a concern, particularly in light of such a dramatic event and one so crucial for America,” Snowe said.

At their news conference, Collins and Lieberman lauded everyone from President Obama to his national security and intelligence team to the Navy SEALs who carried out the raid.

They also touted the immediate “situation awareness” alert that went out at midnight Sunday from the Department of Homeland Security and FBI to local law enforcement authorities as demonstration of the communication and cooperation that was lacking prior to Sept. 11, 2001.

“It shows how far we have come in the past decade,” Collins said.

First District U.S. Rep. Chellie Pingree said there’s a lot to be proud of in what the successful mission against bin Laden means, a decade after 9/11.

But Pingree said the realization that bin Laden was hiding in a populated neighborhood in a Pakistani city near a Pakistani military base — not a remote region in Afghanistan — will prompt questions about the U.S. relationship with Pakistan and its role in the fight against al-Qaida.

Pingree, a member of the House Armed Services Committee, said the bin Laden mission also will raise questions about whether a targeted attack supported by good intelligence is more valuable to the effort to eradicate al-Qaida and other terrorist groups than a “nation building” initiative in Afghanistan, with its associated loss of U.S. lives and enormous expense.

Pingree agreed Americans need to be alert for a retaliatory backlash, but added that, “We can’t underestimate what a blow this has been to an ever-weakening terrorist network” that already has been harmed by pro-democracy movements in the Middle East and North Africa.

Second District U.S. Rep. Mike Michaud called bin Laden’s death “a significant development in the international campaign against al-Qaida.”

But, “while the death of Osama bin Laden is momentous, it doesn’t signify the end to threats against the United States,” Michaud said in a statement Monday afternoon.

MaineToday Media Washington Bureau Chief Jonathan Riskind can be contacted at 791-6280 or at: [email protected]