The Obama administration’s decision to not intervene in Syria and Bahrain stems from a variety of factors, including the perceived risk to U.S. forces, the imperatives of the fight against al-Qaeda, and the need to defend American allies and to keep foreign oil supplies flowing, Secretary of State Hillary Rodham Clinton said Monday night.

“Situations vary dramatically from country to country,” Clinton said in a speech to the National Democratic Institute in Washington, according to her prepared remarks. “It would be foolish to take a one-size-fits-all approach and barrel forward regardless of circumstances on the ground.”

“We’ll always have to walk and chew gum at the same time,” she said.

Clinton said the United States would continue to support transitions to democracy. But it was fair to ask, she said, “Why does America promote democracy one way in some countries and another way in others?”

The administration’s Middle East policy has been criticized as inconsistent and sometimes timid. Republicans have blasted President Obama for what they have portrayed as “leading from behind” in Libya. Many Arabs, meanwhile, have questioned why the United States has called for the resignation of Syrian President Bashar al-Assad, after months of violent attacks against anti-government demonstrators, while adopting a more measured tone about government repression in Bahrain, a U.S. ally that hosts the Navy’s 5th Fleet.

Clinton said Monday that the U.S. decision to participate in a seven-month air campaign in Libya that decimated Moammar Gaddafi’s military was made because dozens of NATO and Arab countries banded together “to protect civilians and help people liberate their country without a single American life lost.”

“In other cases,” she said, “to achieve that same goal, we would have to act alone, at a much greater cost, with far greater risks and perhaps even with troops on the ground.”

In Syria, where Assad has sent security forces to fire on demonstrators and ignored calls from the United States and other nations to step down, the Obama administration has resisted calls for direct intervention.

“Our choices also reflect other interests in the region with a real impact on Americans’ lives — including our fight against al-Qaeda; defense of our allies; and a secure supply of energy,” Clinton said. “There will be times when not all of our interests align . . . that is just reality,” she said.

“That is our challenge in a country like Bahrain,” she said. There, the ruling monarchy has cracked down on Shiite protesters who it says are promoted by Iran.

Both she and Obama, Clinton said, have reiterated that “mass arrests and brute force are at odds with the universal rights of Bahrain’s citizens and will not make legitimate calls for reform go away.”

In neighboring Saudi Arabia, one of the world’s largest oil producers and a key counterterrorism ally, “we have had candid conversations . . . about our view that democratic advancement is not just possible but a necessary part of preparing for the future,” she said.

In Tunisia, where the Arab Spring began late last year and an Islamist party recently won elections, “what parties call themselves is less important than what they do,” Clinton said.