WASHINGTON (CNN) -- The nation's chief intelligence official warned Thursday that a new president's first year in office is the most perilous time for the country.
Mike McConnell, right, appears with President Bush after an intelligence briefing October 24.
"I would say the period of most vulnerability for the United States is the first year of a new president," Director of National Intelligence Mike McConnell told an annual conference of intelligence officials and contractors in Nashville, Tennessee, on Thursday.
McConnell cited the attack on the World Trade Center shortly after Bill Clinton took over the presidency in 1993 and the September 11, 2001, attacks on New York and Washington, which occurred less than eight months after George W. Bush took the oath of office.
McConnell's comments seemed similar to those made recently by Democratic vice presidential candidate Joe Biden, who was criticized when he suggested his running mate Barack Obama would be tested by an international crisis within his first six months in office. Biden referred to it as a "generated crisis to test the mettle" of Obama.
Republican nominee John McCain seized on Biden's remarks, telling supporters, "We don't want a president who invites testing from the world when the economy is in crisis and Americans are already fighting two wars." Obama's campaign responded that Biden raised "the simple fact that history shows presidents face challenges from Day One."
McConnell indicated that presidential candidates have received intelligence briefings with the focus mostly on terrorism. After the election, the new president will immediately begin getting a more comprehensive intelligence briefing -- including details about operations and covert activities -- that is provided President Bush each day.
McConnell said the president-elect's excitement "is going to be dampened somewhat when he begins to focus on the realities of the myriad of changes and challenges we are going to face in the future." One of those "challenges" include the prospect of an attack by a biological agent, which he said might "create casualties greater than 9/11."