A former top U.S. admiral struck a cautiously optimistic tone about the challenges to U.S. security in a lecture Tuesday.

“None of this is going to be easy, none of this is going to be done in a day,” said Admiral William J. Fallon, formerly the commander of U.S. Central Command. “Can it be done? Of course it can.”

Invited by the Center for the Study of Globalization, Fallon spoke to a crowd of about 40 on geopolitical and regional themes. As Commander of CENTCOM, Fallon was responsible for all military activity in the Middle East and Afghanistan from March 2007 to March 2008.

His departure from CENTCOM generated controversy. A March 5, 2008 piece in Esquire magazine suggested that tension between Fallon and the administration of President George W. Bush ’68 arose after Fallon allegedly opposed military escalation with Iran. Asked Tuesday about his 2008 retirement, Fallon expressed frustration with the “crescendo of chatter” following the Esquire piece’s publication, and explained that he left to avoid further controversy.

“The president didn’t need to look at the dilemma of whether he should kiss me or shoot me,” Fallon said Tuesday. “So I said, it’s enough.”

Fallon said he entered the post charged with putting out “two fires” in Iraq and Afghanistan. In Iraq, Fallon said a hard line against al-Qaida elements — and an open hand toward Sunnis — led to progress.

“People are susceptible to changing their minds,” he said. “In 2006, in six months’ time, things accelerated pretty rapidly.”

Fallon said he considered Afghanistan the larger, albeit solvable, challenge. He said the conflict was intrinsically related to developments in Pakistan and struck an optimistic tone. Fallon said the interactions of different tribal groups in Afghanistan were “conducive to a bright outlook.”

Fallon also called for more foreign aid but noted that “it’s a difficult sell” to Congress during a recession. Millions worldwide die of preventable diseases, such as diarrhea, every year, Fallon said.

After having spent decades in the Navy with the Soviet Union as America’s main enemy, Fallon expressed disappointment with post-Cold War developments.

“I looked at the Cold War’s end with a tremendous amount of happiness,” Fallon said. “When this ended, I thought we were moving toward a new era. It hasn’t worked out that way.”

The speech was well-attended. Alexander Martone ’10 said he was impressed by Fallon’s knowledge about the interrelated nature of global issues.

Andrew Kurzrok ’11 said he was hoping for something a little more candid.

“He may still be in political mode,” Kurzrok said. “It would have been nice to hear more of his personal impressions.”

Fallon himself was nearly a Yalie.

“When I had a different color hair, I was accepted to Yale in the 1960s, and was given a Navy scholarship,” he said. “At the last possible day, I changed my mind and matriculated to Villanova.”