The last UK resident held at Guantanamo Bay has spoken out against home-grown terrorists in his first interview since being released.
Mr Aamer, 48, flew back to Britain in October after spending 13 years in the US military facility in Cuba.
He was arrested in Afghanistan in 2001 and accused of working for the Taliban and al-Qaeda.
But like other Guantanamo detainees, he was never charged with an offence. The Saudi-born father of four says he only took his family to Afghanistan in search of a better quality of life.
The allegations against him were dropped as early as 2007.
During more than 5,000 days in captivity, Mr Aamer says he was tortured and held in solitary confinement for nearly a year. He lost half his body weight during a hunger strike in 2005.
He had strong words for Islamic extremists who carry out attacks in Britain, saying: “How can you give yourself the right to be living here in this country, and living with the people and acting like you are a normal person, and then you just walk in the street and try to kill people?”
Commenting on acts of terrorism like the 2013 murder of soldier Lee Rigby, he said Islam did not allow the killing of civilians.
“Even if there is a war you cannot kill just anybody, you cannot kill kids, you cannot kill chaplains, you cannot just go in the street and get a knife and start stabbing people.
“If you are that angry about this country, you can get the hell out.”
He said he was worried about divisions between Muslims and non-Muslims, saying: “It helps their (extremists) cause… if you keep looking at people like they are terrorists before they do anything, then you will push them towards violence.”
Mr Aamer said being reunited with his wife Zinneera “washed away the pain of 14 years”.
“It washed away the tiredness, the agony, the stress. It was like it no longer existed. I hugged her, she hugged me, and we just wept.”
But he said it will take time to forge a bond with his children, the youngest of whom – son Faris, 13 – was born on the day he arrived at Guantanamo in 2002.
Mr Aamer said: “I just wanted to hug them and kiss them. But they were standing stiff. It tore my heart.
“They are shy kids to begin with. But they were looking at me and looking away. It was hard.”
He said he will not be able to forget his time in Guantanamo easily, saying: “It’s always going to be in the back there in my mind, it’s going to be sitting there, coming back from time to time.
“It’s a long period of experience and it can’t be just gone.”
Mr Aamer is now expected to sue the British Government over its alleged complicity in his mistreatment.
SNP foreign affairs spokesman Alex Salmond said the allegation that former Prime Minister Tony Blair and former foreign secretary Jack Straw knew about his “illegal abduction” and “torture” was “not unreasonable”.
He told the BBC’s Andrew Marr Show: “As in so many things Messrs Blair and Straw have a great deal to answer for. They have to be asked a straight question – how could they possibly not have known about the fate that had befallen a British citizen?”
Mr Salmond said few people would doubt that Mr Aamer had been held “illegally and improperly” and remained in Guantanamo “long after everyone knew he had no connection with terrorism whatsoever”.