Republican presidential candidate Mitt Romney smiled and joked with political foe Bill Clinton Tuesday and delivered a speech that subtly criticized President Barack Obama while promising to tie foreign aid to work and free enterprise.

Romney addressed global leaders gathered at the Clinton Global Initiative annual meeting. The GOP White House nominee said U.S. aid needs to be more effective in elevating people and bringing about lasting change in developing nations plagued by instability and violence, including the death of the U.S. ambassador to Libya.

"We somehow feel that we are at the mercy of events, rather than shaping events," Romney said.

Speaking of the Arab Spring and the turbulence in the region, Romney mentioned bloodshed in Syria ("Syria has witnessed the killing of tens of thousands of people"), Egypt ("the president of Egypt is a member of the Muslim Brotherhood"), Libya ("our Ambassador was assassinated in a terrorist attack") and Iran, that is "moving toward nuclear weapons capability", saying that "we feel that we are at the mercy of events, rather than shaping events".

He softened his sharp criticism of Obama at recent campaign rallies and offered a more nuanced critique of U.S. leadership in the world without mentioning the president by name. Instead he laid out a vision for how a Romney administration would lead, including by renegotiating trade agreements and offering "prosperity pacts" in the Middle East and other developing nations to encourage open markets in exchange for U.S. aid.

"The aim of a much larger share of our aid must be the promotion of work and the fostering of free enterprise," Romney said. "Nothing we can do as a nation will change lives and nations more effectively and permanently than sharing the insight that lies at the foundation of America's own economy and that is that free people pursuing happiness in their own ways build a strong and prosperous nation."

In a reflection of his policy on welfare in the United States, Romney said work is the key to lifting people out of poverty abroad by providing self-esteem and a grounding in reality instead of fanaticism. It's a message that also is designed to appeal to white, working-class voters, who Obama has been targeting by dispatching Clinton on the campaign trail.

Clinton gave Romney a warm introduction, which led Romney to jokingly acknowledge that the former president is helping his rival.

"If there's one thing we've learned this election season, it's that a few words from Bill Clinton can do a man a lot of good," Romney said. "All I've got to do now is wait a couple days for that bounce to happen."

A few weeks ago, Clinton offered a forceful defense of Obama's economic record and plans for the future at the Democratic National Convention in Charlotte, N.C.
"I think the president's plan is better than the Romney plan, because the Romney plan fails the first test of fiscal responsibility: The numbers don't add up," Clinton said in that speech, one of several jabs at the Republican.

Romney also referred to the idea of the cultural differences between the nations that sparked Palestinian ire during his visit to Jerusalem last summer - this time, in more general terms. "I became convinced that the crucial difference between these countries wasn’t geography. I noticed the most successful countries shared something in common. They were the freest. They protected the rights of the individual. They enforced the rule of law. And they encouraged free enterprise."

Obama was scheduled to speak to Clinton's group later in the day, after addressing the United Nations General Assembly. Both men were drawing contrasts in a presidential contest in which the state of the U.S. economy has been paramount, but which shifted focus to foreign policy after the recent attack in Libya that killed four Americans.

In his remarks, Romney called the death a terrorist attack, language that Obama himself has not used but that his chief spokesman and secretary of state have.

After the Clinton meeting, Romney planned to discuss education policy at a forum sponsored by NBC News. He also was joining running mate Paul Ryan at a campaign rally in Ohio.