A year ago, Syrian Americans watched with incredulous, dawning hope as a popular uprising began against Syria’s 40-year autocratic regime, inspired by similar protests sweeping other parts of the Arab world. Saturday, they came together in alarm and frustration on that anniversary, begging the Obama administration for help after months of growing repression and bloodshed in their homeland.

Hundreds of people — doctors from Michigan, business owners from New Jersey and Louisiana, teenagers with jeans and cellphones, mothers with Muslim head scarves and baby strollers — gathered in front of the White House for a boisterous but tightly organized rally. Their goal was to call attention to the violence and suffering that continue to worsen in Syria as President Bashar al-Assad clings to power and the West hesitates to intervene­­.

“People are dying, and nobody in America seems to know about it,” said Raya Nashef, 13, who drove from Detroit with her parents for the protest. “I used to go to Syria every summer. It’s beautiful, and it’s my country. I want to be able to go back. I want my relatives to be safe. We want to ask the White House and the world, please get President Assad to step down.”

Waving homemade posters and hundreds of huge white, green and black national flags from the pre-Assad era, the crowd in Lafayette Square clapped and shouted rhythmic chants in Arabic, repeating such slogans as “Syria is for us, not for the Assads,” and “I ask my tears to flow; we’ve paid too much for freedom.”

Despite the emotional mood and rhetoric, it was clear that none of the demonstrators expected Washington to intervene militarily in Syria, a multi-religious country of unique strategic importance in the Middle East. Opposition leaders inside Syria have called for foreign military action, but some experts have warned that a sudden collapse of the regime could have more volatile and far-reaching consequences than the recent ousters of dictators in such countries as Libya and Egypt.

Instead, the protesters asked Washington for more limited and pragmatic assistance, such as putting more pressure on the Damascus government to stop killing civilians and to allow safe zones where emergency aid can be delivered. More than 8,000 people have died in the past year, and far more have been displaced from their homes, as the Assad regime has cracked down on rebels in city after city.

“The level of killing has exceeded the war in Bosnia. We are asking the United States and the free world to act seriously to save lives,” said Hisham Naji, 65, a doctor from Northern Virginia who is regional president of the Syrian American Council, a national advocacy group that organized the rally.

“If they don’t want military intervention, at least do something to allow humanitarian aid to get to people,” he said.

While lamenting the increasingly violent nature of the uprising, which now includes armed insurgents and defected military officers, some protesters defended government opponents for taking up arms, saying they had no choice in the wake of government recalcitrance and international half-measures.

“It’s been a year since Syrians started asking for their freedom, and the regime sent in guns and tanks against them,” said Mazen Hamad, 58, a doctor from Raleigh, N.C. “We tried peaceful demonstrations, diplomacy and negotiations. But a dictator will only listen to force. Right now, Assad is getting mixed messages. They say he must leave but there is no real threat. He needs to feel that threat, or nothing will change.”

The Obama administration has tread cautiously in the Syrian crisis, supporting tough economic sanctions but stopping short of backing the kind of international military effort that toppled Libyan leader Moammar Gaddafi. Washington has been constrained by various factors, from strong opposition by China and Russia to fears of exacerbating regional tensions with Israel and Iran.

Concerns also exist that overthrowing Assad could lead to internal religious conflict among Syria’s ruling Alawite Muslim minority, Sunni Muslim majority and Assyrian Christians. But leaders of Saturday’s rally included members of all these groups, and their message was one of nationwide unity against oppression.

Hamad al-Dabagh, 50, a doctor from Flint, Mich., carried a sign at the rally that said he had lost 10 relatives to repression. His family tragedy went back to 1982, when he was away at college and soldiers slaughtered his father, mother and eight younger brothers and sisters at their home in Damascus. That was during the reign of Assad’s father, Hafez al-Assad, and Dabagh has waited 30 years for justice.

“America has both a moral and strategic reason to help us,” he said. “Today, Assad is doing the same things his father did. If the United States comes to the aid of our revolution, it will win the hearts of the Syrian people, and it will repair much of the damage that was done in Iraq and Afghanistan. The whole Middle East will give them credit.”