WASHINGTON (Reuters) - Five-and-a-half years after the September 11 attacks, President George W. Bush’s war on terrorism has emerged as a wasteful, misguided exercise that poses its own threat to U.S. national security, experts say.

U.S. soldiers secure the area at the site of a local council during their session with U.S. forces to discuss local affairs in Baghdad's northwest Sunni neighbourhood of Ghazaliya March 27, 2007. REUTERS/Fabrizio Bensch

A growing number of analysts and former U.S. officials say the global war on terrorism has undermined U.S. influence abroad, forced onerous costs in American lives and money in Iraq, and unleashed a huge government spending spree that has often funded projects unrelated to national security.

It has also produced a climate of fear in the United States that helped justify the war in Iraq and the curtailment of civil liberties at home, they said.

“The atmosphere of anxiety and uncertainty, and the vagueness of the definition of the enemy, makes the country more fearful and more susceptible to being steered in irrational directions,” said Zbigniew Brzezinski, who was U.S. national security adviser to President Jimmy Carter in the 1970s.

Unlike the muted response to attacks by Britain and Spain, experts say the U.S. has overreacted to the September 11 attacks that killed 3,000 people in New York, Washington and Pennsylvania in 2001.

Congress has spent nearly $271.5 billion on homeland security since September 11, with money often going to projects that have nothing to do with security but that are important to politicians and their constituents, according to a survey by the conservative American Enterprise Institute.

At the same time, the number of potential terrorism targets identified by Congress has exploded from 160 in 2003 to 80,000, allowing such unlikely sites as a Midwestern apple festival and a roadside theme park in Florida to bid for funds.

Meanwhile, the private sector -- lobbyists, interest groups, industries, the media and even universities -- has also used the national security label aggressively to sell its own agendas, experts say.

“What’s clear is that there is no focus whatsoever in the way we are fighting terrorism,” said Veronique de Rugy, author of the AEI study.

Department of Homeland Security spokesman Russ Knocke dismissed the criticism as old and inaccurate, saying the Bush administration had never viewed sites such as small theme parks to be critical national assets deserving of funds. “This has no basis in fact,” he said.

Knocke’s boss, Homeland Security Secretary Michael Chertoff, has also taken issue with the assertion that the U.S. response to September 11 is exaggerated.

“If we begin to heed arguments that somehow our concern about security is overblown ... then I feel we’re going to feel consequences in the loss of lives,” Chertoff said in a speech outlining his priorities for 2007.

But terrorism experts say the United States has yet to develop a clear understanding of the threat posed by al Qaeda and other Islamist militant groups, despite the war on terrorism and a total of $500 billion spent on wars in Iraq and Afghanistan.

The most pernicious effect of the war on terrorism has been the Iraq war, which has claimed the lives of more than 3,200 U.S. troops and tens of thousands of Iraqi civilians and damaged U.S. standing in the Muslim world for generation, experts say.

“Iraq has been vastly worse than anything terrorism’s ever done,” said Ohio State University political science professor John Mueller, author of a book about the war on terrorism titled, “Overblown.”

While both Democrats and Republicans have acknowledged the shortcomings of U.S. policy in Iraq, experts say politicians have not questioned the war on terrorism mainly because it remains a vote-getter.

“Politicians are acting this way because they think they’ll lose votes if they don’t. Basically, it’s a big pork-barrel, so the pork-barrel leaders are there in five seconds,” said Mueller, using American vernacular for the politics of self-enrichment.