London ? Britain’s new security chief warned Sunday that the battle against domestic militancy could take up to 15 years, and said Britons must start sharing information about neighbors they suspect of involvement in terrorism.

Adm. Sir Alan West, the former navy chief who was recently named Prime Minister Gordon Brown’s security minister, said the level of the threat Britain faced was unprecedented and a new approach was critical.

One of those approaches included challenges to the British psyche, he said.

“Britishness does not normally involve snitching or talking about someone,” he told The Sunday Telegraph. “I’m afraid, in this situation, anyone who’s got any information should say something because the people we are talking about are trying to destroy our entire way of life.”

He said preventing the radicalization of young British Muslims was his top priority.

“This is not a quick thing,” he said. “I believe it will take 10 to 15 years. But I think it can be done as long as we as a nation apply ourselves to it and it’s done across the board.”

Meanwhile, authorities acknowledged no armed police were on duty June 30 at Glasgow airport when two men crashed a Jeep Cherokee laden with gas cylinders and gasoline into the main terminal.

“Armed officers are only deployed to the airport when the national threat level requires it,” a Strathclyde police spokesman said on condition of anonymity because department policy barred him from speaking for attribution.

Britain’s terrorism threat level was “severe” at the time of the attack – the second-highest level, which means an attack is highly likely. It remains at that level.

It is up to individual police forces to decide how to deal with the threat level, a Home Office spokeswoman said.