OXON HILL, Md. — The Republican Party's leading presidential contenders on Friday promised conservative activists they would pursue aggressive military action to prevent the spread of global terrorism, including a renewed use of ground forces in the Middle East.
As war-weary critics in both parties watched with skepticism, one Republican White House prospect after another attacked President Obama's foreign policy as far too timid as they courted thousands of conservative activists gathered in suburban Washington.
"Our position needs to be to re-engage with a strong military and a strong presence," former Florida Gov. Jeb Bush told the Conservative Political Action Conference.
Bush added he liked the option of sending ground forces into the fight against the Islamic State group, particularly to conduct intelligence and special operations. "As we pull back, voids are filled," Bush said.
Foreign policy was largely an afterthought in the last presidential election, but it has become a dominant theme in the early stages of the Republican race, with most of the party's White House prospects calling for a far more muscular foreign policy than under Obama.
The large crowd at CPAC cheered the repeated jabs at the Democratic president, but they booed at times when speakers called for ground troops to fight Islamic State militants — a reminder that many voters are reluctant to put American troops at risk after more than a decade of war in Iraq and Afghanistan.
Former Texas Gov. Rick Perry described the Islamic State group as "the worst threat to freedom since communism," and he declined to rule out sending American ground forces in the region.
Florida Sen. Marco Rubio said the U.S. must "put together a coalition of armed forces from regional governments to confront them on the ground, with U.S. special operations support, and then provide logistical support, intelligence support and the most devastating air support possible."
None of those who called for the use of U.S. ground forces against the Islamic State group specified whether they meant putting troops in the territory the militants control in Iraq, where the government has sought U.S. help, or in Syria.
The U.S. has called for the ouster of Syrian President Bashar Assad and is conducting airstrikes in his country without his cooperation. Ground troops would be considered an invading force by the embattled Syrian government.
There was also a word of caution from Kentucky Sen. Rand Paul, a favorite of the libertarian-leaning CPAC crowd, which generally favors a smaller U.S. footprint in the world.
"I envision an America with a national defense unparalleled, undefeatable and unencumbered by nation building," Paul said. "As conservatives, we should not succumb to the notion that a government inept at home will somehow become successful abroad."
Rubio used part of his time on stage to criticize Obama's foreign policy for not being sufficiently supportive of Israel. The Obama administration and its allies are in negotiations with Iran to curb Tehran's nuclear program, an effort that Rubio said was destined to fail.
"It is a foreign policy that treats the ayatollah of Iran with more respect than the prime minister of Israel," Rubio said.
Not unexpectedly, the Republicans drew criticism from Democrats who said few of the speakers had significant foreign policy experience, a point that some Republican contenders are working to address by studying international affairs with newly added advisers and taking trips abroad.
"From comparing American workers to terrorists, to advocating that our brave men and women be stationed in Iraq indefinitely, to supporting the elimination of all foreign aid including to our allies like Israel, there is not a single Republican presidential hopeful who can be trusted to oversee our national security," said Democratic National Committee spokesman Holly Shulman.
Shulman was referencing Walker, who suggested on Thursday that his political fight with labor union protesters in Wisconsin helped prepare him to combat global terrorism as president.
Bush suggested in a December speech that between 5,000 and 10,000 troops should have been left in Iraq. Paul has proposed budgets that eliminate all foreign aid, including funding to Israel.
Pointing to countries such as Pakistan on Friday, Paul said American taxpayer dollars should not go to nations that challenge the United States. "I say not one penny more to these haters of America," Paul said.
Polls suggest that voter opinions about foreign policy have evolved dramatically over the last two years, even within the GOP. More than half of Republicans said the U.S. does too much to solve the world's problems in a 2013 Pew poll. But by August 2014, that number had dropped to 37 percent.
A January Associated Press-GfK poll found almost half of Republicans in favor of sending ground troops against the Islamic State group in Iraq and Syria.
There were also signs of a growing willingness to embrace military action among the young activists who clogged the hallways outside the main ballroom where the likely candidates spoke.
"When things start to heat up, I think it's time that you should start to step in," said Ashley Bullard, 22, a Rand Paul supporter and student at Eastern Connecticut State University.
"After a while," she said, "I think enough is enough."
Associated Press writers Jill Colvin and Philip Elliott contribute to this report.