He told US network NBC that use of the interrogation technique waterboarding - simulated drowning - had prevented terrorist attacks and saved lives.
Mr Bush, who is is publicising his memoir Decision Points, said the invasion Iraq in 2003 was not wrong.
History would judge him a success, he added, but he would be dead by then.
"I just didn't want to get out there anymore," he told NBC's Matt Lauer of his absence from the media since he left the White House in January 2009.
"I didn't want to get back into what I call 'the swamp'," he said.
On the interrogation of terror suspects, he said his legal adviser had told him that the use of waterboarding on several Guantanamo inmate prison was legal.
"He said it did not fall within the anti-torture act. I'm not a lawyer. But you've got to trust the judgement of people around you, and I do," Mr Bush said.
"I will tell you this: using those techniques saved lives. My job was to protect America. And I did."
Mr Lauer asked him of the "sickening feeling" he describes in Decision Points every time he thinks about the failure to find weapons of mass destruction in Iraq after the 2003 invasion that toppled Saddam Hussein.
"Was there ever any consideration of apologising to the American people?" Mr Lauer asked.
"I mean, apologising would basically say the decision was a wrong decision," Mr Bush replied. "And I don't believe it was the wrong decision."
He said it might be some time before history is able to judge his presidency.
"I hope I'm judged a success. But I'm gonna be dead, Matt, when they finally figure it out," he said.
In his memoir, Mr Bush admits the economic woes he left to his successor, Barack Obama, were "one ugly way to end a presidency".
But he rejects accusations that the bailout of the banks, known as Tarp - the Troubled Asset Relief Program - was a waste of public money.
"Tarp sent an unmistakable signal that we would not let the American financial system fail," he asserts.
But in the final months of his presidency, he still hoped the United States might avoid a recession, he writes, even as "the house of cards was about to come tumbling down".
But he defends his economic policies against charges by fiscal conservatives - including the Tea Party movement - who say he squandered the surplus left by the outgoing Clinton administration in 2001.
"Once the recession and 9/11 hit, there was little surplus left," Mr Bush writes.
In the television interview, Mr Bush also revealed he fell out with his vice-president, Dick Cheney, in a row over whether to pardon Mr Cheney's top aide.
Mr Bush refused to pardon Lewis "Scooter" Libby, who was convicted of perjury and obstruction in connection with the leaking of the identity of a CIA spy.
But Mr Bush said his friendship with Mr Cheney had recovered.