As the U.S. prepares to withdraw from Afghanistan, domestically the government feels that threats are increasing. Despite taking down no fewer than three key al-Qaeda members in the last year, the U.S. has doubled the size of its notorious no-fly list.

Government figures provided to The Associated Press this week reveal that the no-fly list that was created over a decade ago as a response to the September 11 terrorist attack has more than doubled in size in only one year’s time. In 2011, the roster of red-flag would-be fliers included only around 10,000 names. The AP has now learned, however, that today the list has extended to include around 21,000 individuals.

Timothy Healy, director of the Terrorist Screening Center, tells the AP that a series of improvements were made to the criteria that could land a suspicious person on the agency’s list after the failed Christmas 2009 bombing over Detroit, Michigan. The U.S. government does not disclose what qualifying factors place persons on the list of suspicious persons, however, nor does it provide a roster of those included though.

Upon formally ending the War in Iraq this past December and executing Osama bin Laden, why the US is only feeling more at risk suggests that even as the nation’s wars end abroad, terrorism threats still remain rampant.

Only one day before the AP released their findings, Defense Secretary Leon Panetta announced that he hoped to end U.S. combat operations in Afghanistan nearly a year ahead of time, forfeiting a decade-long operation that began at the same time that the U.S. government official began it’s no-fly list.

“Both U.S. intelligence and law enforcement communities and foreign services continue to identify people who want to cause us harm, particularly in the U.S. and particularly as it relates to aviation,” Transportation Security Administrator John Pistole explains to the AP.

Only one year after being introduced, the no-fly list grew to roughly 1,000 names in late 2002. Nearly ten years later though, the list is more than 20-times that size, although the U.S. claims to have all-but dismantled al-Qaeda, the group formerly led by Osama bin Laden and initiated the 9/11 terror attacks.

Some suspect that the list does not necessarily suggest that the wars on insurgent forces are proved worthless, but that the U.S. government is only making it easier to keep its own citizens from boarding planes. It is believed that the list currently includes around 500 Americans, but as with all names on the list, their identities remain restricted to only the eyes of the U.S. government.

“The news that the list is growing tells us that more people’s rights are being violated,” Nusrat Choudhury of the American Civil Liberties Union adds to the AP. “It’s a secret list, and the government puts people on it without any explanation. Citizens have been stranded abroad.”

Previously, the ACLU has attempted to sue the United States government from barring Americans from air travel without revealing their reasoning in-depth. The organization waged a legal battle with both the U.S. Department of Justice and Federal Bureau of Investigation in 2010 over what staff attorney Ben Wizner said were “un-American and unconstitutional” actions from the U.S. government.

Among those represented by the ACLU are several veterans of the U.S .military who have unexplainably ended up on the no-fly list and been denied entry to their own country. The ACLU has fought in the past for Ayman Latif, a U.S. citizen and Marine vet living in Egypt, and Raymond Earl Knaeble, a U.S. citizen and Army vet who is stuck in Colombia.

When the ACLU waged their suit in 2010, at the time the no-fly list was only 8,000-names large.

Responding to this week’s news, the ACLU writes on Thursday that “To deprive people of their right to travel without any notice or opportunity to object is unfair and unconstitutional. The news that the list is getting bigger only magnifies the problem.”