(PhysOrg.com) -- The government's own secrets, lies and conspiracies have fueled a 45-year-long decline in America's trust in its leaders, a University of California, Davis, history professor argues in a new book.

Among the bizarre-but-documented conspiracies: U.S. plots to kill Cuban president Fidel Castro (one scheme involved dropping poison pills in his drinks; another called for planting an exploding seashell in his favorite scuba-diving bay); proposed military attacks on U.S. citizens as a pretext for war with Cuba (bombing U.S. cities, for one; blowing up John Glenn's rocket during his historic spaceflight, for another); and a study that dropped into the drinks of unsuspecting Americans in random bars.

Kathryn Olmsted outlines these and other in "Real Enemies: and American , World War I to 9/11," her third book on secrets and lies in government and politics. It was published this month by Oxford University Press.

"Isn't everyone interested in secrets and lies?" Olmsted says of her research focus. "Conspiracy theories are really a window into a culture."

And the view through that window is one of growing paranoia. Olmsted notes that in a 1964 poll, nearly 80 percent of Americans said that they trusted officials to do the right thing most or all of the time -- an all-time high.

Contrast that with 2006, when more than half of Americans ages 18 to 29 told pollsters they believed that the Bush administration had either planned the 9/11 attacks or deliberately let them happen.

In "Real Enemies," Olmsted traces this rampant suspicion to post-World War I growth in government size, power and secrecy.

She notes that in 1913, the total federal budget was less than $1 billion, the fledgling Bureau of Investigation had no responsibility for suppressing dissent, and few Americans regarded the government as big or strong enough to merit fear.

But just five years later, the federal government controlled a $13 billion budget, oversaw several agencies charged with countering subversion, and, under the Sedition Act of 1918, possessed the power to arrest anyone who said or printed anything that was "disloyal" or "contemptuous" of the government.

"Some Americans had worried for decades that malign forces might take over the government," Olmsted writes in the book. "Now, with the birth of the modern state, they worried that the government itself might be the most dangerous force of all."

"Real Enemies" charts the continued growth in state power through the 20th century, including the McCarthy era, Cold War and Vietnam War. The second half of the century saw the CIA plotting Castro's murder with the mafia, the FBI spying on civil rights leaders, and a president, Nixon, conspiring to use state power to punish his personal enemies.

"By the end of the 1970s, Americans knew more about their government's secrets and misdeeds than any people in ," she writes. "And the more they learned, the more they suspected that the government was still hiding bigger, more explosive secrets."

After the start of the Iraq War, suspicion was so high that Americans were willing to give credence to the idea that President Bush had a hand in the terrorist attacks of Sept. 11, 2001. Olmsted divides these conspiracy theorists into two camps: the LIHOP, who believed that Bush "let it happen on purpose," and the MIHOP, who believed he "made it happen on purpose."

"Real Enemies" builds on Olmsted's previous books: "Challenging the Secret Government: The Post-Watergate Investigations of the CIA and FBI" and "Red Spy Queen: A Biography of Elizabeth Bentley."

Research for "Real Enemies" consumed five years and required combing through thousands of pages of congressional transcripts and once-classified government documents. Olmstead also visited university libraries around the country to sift through the private papers of prominent conspiracy victims and theorists, including scientist Linus Pauling, who faced FBI harassment as a suspected communist during the Cold War, and Sylvia Meagher, an analyst for the World Health Organization who devoted herself to disproving the government's account of John F. Kennedy's assassination.

The cure for corrosive conspiracy theories, according to Olmsted, is increased government transparency and accountability. And Americans must make themselves informed skeptics.

"When you live in a democracy, you have to educate yourself about your government to hold it accountable," the history professor says. "I always tell my students that being a citizen in a democracy is a lot of work. You have to be skeptical of your government, and you have to be skeptical of conspiracy theories about your government. Trusting either totally is a mistake."

Provided by UC Davis