Osama bin Laden is dead and there hasn't been a successful attack by al-Qaida-inspired extremists on U.S. soil since the deadly shooting rampage in Fort Hood, Texas, in 2009. But the danger of terrorism remains a reality for Americans, as seen in the attack in Libya in September that killed U.S. Ambassador Chris Stevens and three other Americans. The terrorist assault on the 11th anniversary of 9/11 injected the issue of diplomatic security into the presidential campaign and renewed questions about the quality of U.S. intelligence.
Also a reality: the huge expense of homeland security more than a decade after 9/11, the cost to privacy and civil liberties from aggressive surveillance in the U.S. and the toll in innocent lives from U.S. drone attacks that have killed a succession of known and suspected terrorists.
Where they stand:
President Barack Obama, who approved the raid that killed bin Laden, set a policy to end the use of harsh interrogation tactics. But he's greatly expanded drone attacks and is calling for the renewal of surveillance powers put in place after the 2001 attacks. He failed to close the Guantanamo Bay, Cuba, detention camp as promised. Republican Mitt Romney has said little about terrorism in the campaign. But in the past he's said he doesn't think waterboarding is torture. Republicans also are pressing for answers on why Washington rejected requests for heavier security at the U.S. Consulate in Benghazi, Libya, before the deadly assault.
Why it matters:
Terrorism is not as great a concern for voters this election as in the past, according to polls. But that will change in a heartbeat if terrorists manage to pull off anything on a large scale or if overseas attacks like the one in Libya keep happening.
A trip through an airport may be the most tangible reminder of the impact of terrorism on Americans. Anyone who flies commercial airlines knows what it's like to have to take off their shoes and walk through body-imaging machines. The government says these security measures are necessary because terrorists continue to target airplanes and develop new methods and weapons to evade U.S. security.
There are less visible aspects of anti-terrorism, too, such as secret surveillance at home and military operations abroad.
The al-Qaida of Sept. 11, 2001, has been greatly degraded. But new, like-minded groups are becoming growing threats. And people who live in the U.S. are not immune to their messages. Dozens of Americans, inspired by al-Qaida's ideology, are known to have plotted to kill innocent people inside the U.S. and abroad. There is a fine line between expressing one's opinion, however hateful, and being motivated to commit violence. The government is constantly trying to identify the latter.
To catch terrorists before they strike, the Obama administration wants to renew a program to monitor terrorism suspects' international communications. That means at times snooping on the communications of law-abiding Americans. It's not known how often.
The government has also expanded the use of unmanned drone strikes in Pakistan and Yemen. These not only hit the intended targets, but have killed innocent civilians nearby.
And the government has no shortage of secret lists, many including Americans.
One list includes suspected American terrorists whom the U.S. has authorized itself to kill or capture. The justifications for that authorization are as secret as the names on the list. The government also has suspected terrorists on a no-fly list. This list ballooned under Obama and continues to grow. Though the list includes about 500 Americans, there is no official process to determine whether you are on it and whether it's for legitimate reasons.