US-UK Row Reopens Over 'Dangerous' Ex-Guantanamo Detainee Shaker Aamer

A transatlantic row has flared up again over Shaker Aamer, the Guantanamo Bay detainee released to the UK in October, who has been described by a US senator as "a dangerous man who seeks to harm the United States."

Arkansas Senator Tom Cotton claimed this week that Aamer was not transferred to the UK with the full agreement of the government and military, and suggested that his relocation has implications for US national security.

Former UK International Development Secretary Andrew Mitchell told VICE News on Friday, however, that the US case against Aamer had been "discredited" and that the UK has the relevant intelligence and facilities "to do all that is necessary to look after Aamer."

Cotton was among 10 US senators who wrote to the Pentagon and military chiefs in November asking why the joint chiefs of staff (JCS) apparently withheld their approval for the release of British resident Aamer from Guantanamo.

A response from US Defense Secretary Ash Carter was published on Cotton's website on Wednesday. Carter acknowledged that Martin Dempsey, then-Chairman of the JCS had raised "some concerns that Aamer might reengage in terrorist activity" after his transfer.

"Although I share concerns about the re-engagement of any detainee in terrorist activities," wrote Carter, "taking into considerations the security assurances that would be provided by the United Kingdom, I determined that transferring Aamer to the United Kingdom was in the national security interest of the United States.

"The government of the United Kingdom is one of our strongest and most capable counterterrorism partners and our closest ally."

Related: Shaker Aamer, the Last Remaining UK Guantanamo Detainee, Has been released

Carter's letter echoed the findings of the six-agency task force which agreed Aamer's release prior to Dempsey being sworn in on October 1, 2011.

"With respect to the press release concerning Aamer, it stated that the Guantanamo Review Task Force… unanimously designated Aamer as eligible for transfer, subject to appropriate security measures and other conditions," he wrote.

In a press statement Cotton described Carter's response as "disappointing," and claimed Aamer "is a dangerous man who seeks to harm the United States."

"That he was transferred with anything less than full agreement of our government and our military is completely unacceptable and speaks volumes about President Obama's commitment to political talking points over our national security," he said.

Aamer's transfer was arranged after intense lobbying from a cross-party committee of MPs, including Mitchell, who told VICE News last May that Aamer's continued detention by the US was "insulting to their oldest ally."

On Friday, Mitchell dismissed Cotton's claims to VICE News: "First of all, the United Kingdom has the relevant intelligence and facilities, both intelligence and health, to do all that is necessary to look after Aamer."

"Secondly, the US administration should be honoring the president's first commitment when elected to office to shut Guantanamo Bay — which is a hideous carbuncle on the face of justice and human rights.

"Rather than supporting the discredited US case against Aamer, perhaps the senator could deploy his undoubted talents to supporting his president's earlier objective in respect of Guantanamo bay," Mitchell added.

Related: The US Still Hasn't Released Shaker Aamer from Guantanamo, and It's 'Insulting' the UK

Clive Stafford Smith, lawyer for Aamer with human rights organization Reprieve, also dismissed Cotton's claims as "outrageous."

"Aamer has been abused in Guantanamo for 13 years," he said. "He's just trying to quietly reconstruct his life and build a relationship with one child he'd never met and three children who he hadn't seen since they were four years old.

"Whenever we talk about Guantanamo Bay, the Republicans are going to use it as a political football. They want to foment discord and that's what this is about.

"Senator Cotton is most welcome to come to Britain to sit down with Aamer and see if what he's saying is true."

Follow Ben Bryant and Namir Shabibi on Twitter: @benbryant and @nshabibi