Some change doesn't come easy.
President Obama pledged during the 2008 campaign to fix the "failed policies" of the "disastrous" Bush administration. But in his first 100 days in the White House he has not fully thrown off the mantle of his predecessor -- nor shown him to be a failure, foreign policy experts say.
Obama has clashed with George W. Bush on many of the issues that defined the 43rd president's tenure: on commitments in Iraq, engaging with Iran and other enemies, on the harsh interrogation of suspected terrorists.
From his first days in office, Obama set about undoing the architecture of Bush's War on Terror -- objecting to his overarching approach to fighting Islamist terrorism and even to the phrase "War on Terror" itself, which has been shunned by the new administration.
But few of those changes have had a visible effect three months in: the naval prison at Guantanamo Bay was ordered closed yet remains open as Obama plans where to send its inmates; the president has yet to establish a coherent policy on Iran -- following in the Bush administration's frustrated footsteps; and while American troops are being removed from Iraq, most will stay in place until 2010.
Gary Schmitt, director of advanced strategic studies at the American Enterprise Institute, said the 2007 surge of troops in Iraq and the employment of counterinsurgency tactics there made room for a safer withdrawal from the country. "The very fact that he can pull troops out of Iraq and do so in the timeline that he's talked about is evidence of Bush's policy success there," he said.
Obama's planned withdrawal has slowed as he responds to the situation on the ground, which some foreign policy experts are greeting as a welcome sign of his pragmatism.
"I don't think they came in with their minds made up -- I don't think they feel committed to an ideological stance," said Stephen Biddle, senior fellow for defense policy at the Council on Foreign Relations, praising Obama as a corrective to the excesses of his predecessor.
"I think they're trying to make a reasoned call in light of information about the situation," he told FOXNews.com.
But the careful deliberation Biddle praised has slowed the formulation of Iran policy, which remains an undefined balance of sticks and carrots for the nation the United States considers the leading exporter of terrorism and believes is in pursuit nuclear weapons.
Secretary of State Hillary Clinton said Wednesday the United States is preparing "crippling" sanctions for Iran if it does not respond to diplomatic outreach. But so far the president's outstretched hand has been slapped away by Iran's religious and political leaders.
"The problem is not a lack of U.S. engagement," said James Phillips, senior fellow for Middle Eastern affairs at the Heritage Foundation. "The Carter administration, the Reagan administration and the Clinton administration all tried to varying degrees to engage Iran but failed after the Iranians rejected or sabotaged those diplomatic efforts."
Obama has pledged to reach out even to our enemies, including Venezuelan President Hugo Chavez, a longtime thorn in the U.S. side. Obama greeted Chavez warmly at a Summit of the Americas in Trinidad last week, prompting outrage from his opponents over his embrace of an increasingly bellicose authoritarian.
The friendly encounter was part of a learning curve for Obama, and his overall embrace of multilateralism could reap rewards in Latin America, said Michael Shifter, vice president for policy at the Inter-American Dialogue.
"I think that if the Obama administration in general improves its relationships with other Latin American governments there will be more opportunities to ... have other governments join with the U.S. to press Venezuela," he told FOXNews.com.
Shifter and many other analysts called the summit a "missed opportunity" to pressure Chavez, who has been cracking down on democratic dissent in his own country since before Obama took office. That failure points to a lack of a clear policy for handling Chavez, much as is the case in Iran, experts say.
"We can't say it's a failure or success yet because they really don't have a policy in place," Schmitt said.
Already solidified is Obama's stance on terror detainees, whom Bush kept locked up at Guantanamo Bay and in secret CIA prisons around the world. Obama ordered those closed on his second full day in office and has called his continued ban on enhanced interrogations "the end of a dark and painful chapter in our history."
But some terrorism experts say the easing of pressure on terror suspects and the planned release of Guantanamo detainees endangers the United States -- and that Obama is not as serious about security issues as Bush was.
Obama is rejecting techniques that bore great fruit, said Andrew McCarthy, chairman of the Center for Law and Counterterrorism at the Foundation for Defense of Democracies. "All the enhanced interrogation tactics that we used actually yielded crucially important intelligence that helped keep this country safe," he said, citing the eight years of safety on the home front since Sept. 11, 2001.
Obama's own Director of National Intelligence, Dennis Blair, wrote an internal memo last week citing the "high value" information about Al Qaeda's operations yielded by tactics such as waterboarding, but its morality has been called into question by human rights monitors and many others both in and out of the Obama administration.
Though foreign policy experts disagree on the proper benchmarks for success in comparing Obama to Bush, that clearest challenge will remain in place -- to keep his country safe from attack for the 1,360 or more days remaining in his term.