Terror threat the biggest change in 20 years: John Howard

The threat of terrorism remains the biggest single change in Australian society in the 20 years since he was elected, former prime minister John Howard says.

Mr Howard, who celebrates the 20th anniversary of his election at a dinner in Parliament House on Wednesday, said in March 1996 we were still living in the warm afterglow of the collapse of the Soviet Union and the fall of the Berlin wall.

"Some people even said it was the end of history but all that was to change very dramatically on 11 September 2001. So that's the biggest single change without any doubt. There are others but that stands above everything else," he told ABC Television.

Mr Howard said that did not mean Australians were less safe, because of preventative measures including improvements in intelligence.

"You've always got to look at what might have happened if we hadn't taken preventative measures and I think we are going to live with the threat of terrorism for decades into the future, just as we lived with the Cold War and the threat of nuclear annihilation," he said.