The State Department under Hillary Clinton fought hard against placing the al Qaeda-linked militant group Boko Haram on its official list of foreign terrorist organizations for two years. And now, lawmakers and former U.S. officials are saying that the decision may have hampered the American government’s ability to confront the Nigerian group that shocked the world by abducting hundreds of innocent girls.

In the past week, Clinton, who made protecting women and girls a key pillar of her tenure at the State Department, has been a vocal advocate for the 200 Nigerian girls kidnapped by Boko Haram, the loosely organized group of militants terrorizing northern Nigeria. Her May 4 twee t about the girls, using the hashtag #BringBackOurGirls, was cited across the media and widely credited for raising awareness of their plight.

On Wednesday, Clinton said that the abduction of the girls by Boko Haram was “abominable, it’s criminal, it’s an act of terrorism and it really merits the fullest response possible, first and foremost from the government of Nigeria.” Clinton said that as Secretary of State she had numerous meetings with Nigerian President Goodluck Jonathan and had urged the Nigerian government to do more on counterterrorism.

What Clinton didn’t mention was that her own State Department refused to place Boko Haram on the list of foreign terrorist organizations in 2011, after the group bombed the U.N. headquarters in Abuja. The refusal came despite the urging of the Justice Department, the FBI, the CIA, and over a dozen senators and congressmen.

“The one thing she could have done, the one tool she had at her disposal, she didn’t use. And nobody can say she wasn’t urged to do it. It’s gross hypocrisy,” said a former senior U.S. official who was involved in the debate. “The FBI, the CIA, and the Justice Department really wanted Boko Haram designated, they wanted the authorities that would provide to go after them, and they voiced that repeatedly to elected officials.”

In May 2012, then-Justice Department official Lisa Monaco (now at the White House) wrote to the State Department to urge Clinton to designate Boko Haram as a terrorist organization. The following month, Gen. Carter Ham, the chief of U.S. Africa Command, said that Boko Haram “are likely sharing funds, training, and explosive materials” with al-Qaeda in the Islamic Maghreb. And yet, Hillary Clinton’s State Department still declined to place Boko Haram on its official terrorist roster.

Secretary of State John Kerry eventually added Boko Haram and its splinter group Ansaru to the list of foreign terrorist organizations in November 2013, following a spate of church bombings and other acts that demonstrated the group’s escalating abilities to wreak havoc.

‪Being placed on the State Department’s list of foreign terrorist organizations allows U.S. law enforcement and intelligence agencies to use certain tools and authorities, including several found in the Patriot Act. The designation makes it illegal for any U.S. entities to do business with the group in question. It cuts off access to the U.S. financial system for the organization and anyone associating with it. And the designation also serves to stigmatize and isolate foreign organizations by encouraging other nations to take similar measures.

The State Department’s refusal to designate Boko Haram as a terrorist organization prevented U.S. law enforcement agencies from fully addressing the growing Boko Haram threat in those crucial two years, multiple GOP lawmakers told The Daily Beast.

“For years, Boko Haram has terrorized Nigeria and Western interests in the region with few consequences,” Sen. James Risch told The Daily Beast on Wednesday. “The U.S. government should have moved more quickly to list them as a terrorist organization and brought U.S. resources to track and disrupt their activities. The failure to act swiftly has had consequences.”

Risch and seven other GOP senators introduced legislation in early 2013 that would have forced Clinton to designate the group or explain why she thought it was a bad idea. The State Department lobbied against the legislation at the time, according to internal State Department emails obtained by The Daily Beast.

In the House, leading intelligence-minded lawmakers wrote letter after letter to Clinton urging her to designate Boko Haram as terrorists. The effort in the House was led by then-Homeland Security Committee Chairman Peter King and Patrick Meehan, chairman of the Subcommittee on Counterterrorism and Intelligence.

Meehan and his Democratic counterpart Jackie Speier put out a lengthy report in 2011 laying out the evidentiary basis for naming Boko Haram a terrorist organization, including the group’s ties to al Qaeda in the Islamic Maghreb and to Somalia’s al-Shabab terrorist organization.

In an interview Wednesday, Meehan told The Daily Beast that if Clinton had placed Boko Haram on the terrorism list in 2011, U.S. law enforcement agencies now being deployed to Nigeria to help search for the girls might have been in a better position.

“We lost two years of increased scrutiny. The kind of support that is taking place now would have been in place two years ago,” he said. The designation would have “enhanced the capacity of our agencies to do the work that was necessary. We were very frustrated, it was a long delay.”

Moreover, Meehan and others believe that the Clinton State Department underestimated the pace of Boko Haram’s growth and the group’s intention to plan operations that could harm U.S. critical interests abroad.

“At the time, the sentiment that was expressed by the administration was this was a local grievance and therefore not a threat to the United States or its interests,” he said. “They were saying al Qaeda was on the run and our argument was contrary to that. It has metastasized and it is actually in many ways a growing threat and this is a stark example of that.”

Not everyone agrees that Clinton’s failure to act had significant negative effects. A former senior U.S. counterterrorism official told The Daily Beast that despite the State Department’s refusal to put Boko Haram on the terrorism list, there were several other efforts to work with the Nigerian government on countering the extremist group, mainly through diplomatic and military intelligence channels.

“Designation is an important tool, it’s not the only tool,” this official said. “There are a lot of other things you can do in counterterrorism that doesn’t require a designation.”

Had Clinton designated Boko Haram as a foreign terrorist organization, that wouldn’t have authorized any increased assistance to the Nigerian security forces; such assistance is complicated by the Leahy Law, a provision that prevents the U.S. from giving weapons to foreign military and police units guilty of human rights violations.

“The utility was limited, the symbolism was perhaps significant, but the more important issue was how we were dealing with the Nigerians,” this official said, noting that three Boko Haram-related individuals were personally sanctioned during Clinton’s time at State.

Meehan and his Democratic counterpart Jackie Speier put out a lengthy report in 2011 laying out the evidentiary basis for naming Boko Haram a terrorist organization, including the group’s ties to al Qaeda in the Islamic Maghreb and to Somalia’s al-Shabab terrorist organization.

In 2012, more than 20 prominent U.S. academics in African studies wrote to Clinton, urging her to not to label Bok Haram as a foreign terrorist organization. “An FTO designation would internationalize Boko Haram’s standing and enhance its status among radical organizations elsewhere,” the scholars said.

Inside the Clinton State Department, the most vocal official opposing designating Boko Haram was Assistant Secretary of State for African Affairs Johnnie Carson, who served in that position from 2009 to 2013. Several officials said that the Nigerian government was opposed to the designation and Carson was focused on preserving the relationship between Washington and Abuja.

Carson defended the decision to avoid naming Boko Haram a terrorist organization in a Wednesday phone call with reporters.

“There was a concern that putting Boko Haram on the foreign terrorist list would in fact raise its profile, give it greater publicity, give it greater credibility, help in its recruitment, and also probably drive more assistance in its direction,” he said.

The U.S. has plenty of ways to assist the Nigerian government with counterterrorism even without designating Boko Haram, Carson said. The problem has long been that the Nigerian government doesn’t always want or accept the help the U.S. has offered over the years.

“There always has been a reluctance to accept our analysis of what the drivers causing the problems in the North and there is sometimes a rejection of the assistance that is offered to them,” Carson said. “None of that has anything to do with putting Boko Haram on the foreign terrorist list.”

Twenty female senators wrote to President Obama Tuesday urging him to now push for Boko Haram and Ansaru to be added to the United Nations Security Council al Qaeda sanctions list. (Earlier this year, Boko Haram’s leader express solidarity with al Qaeda affiliates in Afghanistan, Iraq, North Africa, Somalia and Yemen, according to the SITE Monitoring Service, which tracks jihadist communications.)

“In the face of the brazen nature of this horrific attack, the international community must impose further sanctions on this terrorist organization. Boko Haram is a threat to innocent civilians in Nigeria, to regional security, and to U.S. national interests,” the senators wrote.

The White House said President Obama will in fact push for Boko Haram to face additional sanctions, including at the UN.

“Boko Haram, the terrorist organization that kidnapped these girls, has been killing innocent people in Nigeria for some time,” National Security Council spokesman Jonathan Lalley told The Daily Beast in a statement. “We’ve identified them as one of the worst regional terrorist organizations out there. That’s why last November we designated them as a Foreign Terrorist Organization and as Specially Designated Global Terrorists. And we're are urging additional multilateral action against Boko Haram—including by working with Nigeria to press for UN Security Council sanctions."

Representatives for Clinton did not respond to multiple requests for comment.

Related: Up to Speed: What’s Happening to Nigeria’s Kidnapped Girls?