Ferguson said that in New Zealand, cooperation with the U.S. improved markedly after the Sept. 11, 2001, terrorist attacks. Still, he said, his agency was kept on a need-to-know basis. He said he never knew what information was being provided to other Five Eyes nations, and none of the countries would have shared all their intelligence anyway.
Ferguson said a small country like New Zealand benefited by a ratio of about five-to-one in the information it received compared to what it provided. He said that as chief of the defense force, a role he held before taking over the spy agency in 2006, he could never have sent troops to Afghanistan without the on-the-ground intelligence provided by the U.S. and other allies. He said New Zealand continues to rely on Five Eyes information for most of its overseas deployments, from peacekeeping to humanitarian efforts. The intelligence is vital, he added, for thwarting potential cyber threats.
In Australia, prosecutors in 2009 used evidence from a U.S. informant who had been at a terrorist training camp in Pakistan to help convict one of nine Muslim extremists found guilty of planning to bomb an unspecified Sydney target. The Australian Security Intelligence Organisation wrote in an email to The AP that "intelligence sharing between countries is critical to identifying and preventing terrorism and other transnational security threats."
Canada's Department of National Defence had a similar response, saying it "takes an active role in building relationships with allies. Collaborating with the personnel of the Five Eyes community in support of mutual defense and security issues is part of this relationship building."
Both agencies declined requests to provide more specific information.
In the decades since World War II, the allies have formed various other intelligence allegiances, although few as comprehensive or deep as Five Eyes. While the Snowden revelations will test the relationship, it has survived tests in the past.
New Zealand has long asserted an independent foreign policy by banning nuclear ships, and some are now calling for the country to go further and opt out of Five Eyes. Lawmaker Russel Norman, co-leader of New Zealand's Green Party, is one of many people calling for a public review of the relationship.
"I want to live in a free society, not a total surveillance state," he said. "The old Anglo-American gang of five no longer runs the world."
But John Blaxland, a senior fellow at the Australian National University's Strategic and Defence Studies Centre, said politicians Down Under have often criticized the security relationship until they've gotten into power and been briefed on its benefits.
Then, he said, they tend to go silent.
"The perception is that the advantages are so great, they'd be crazy to give it up," he said.
Dodds reported from London. Associated Press writers Lara Jakes and Matt Apuzzo in Washington and Rob Gillies in Toronto contributed to this report.
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