Ushering in democracy may be significantly harder. But American support for Yemen’s transition appears to be as much a matter of US security interests as the lofty ideals of the Arab Spring.

The transition starts next week when Abed Rabbo Mansour Hadi is rubber-stamped as Yemen’s new leader, ending 34 years of one-man rule under Saleh, a polarizing figure who craftily kept his opponents divided for decades before the protests across North Africa and the Middle East caught up with him.

The United States is keen to see stability prevail in the Arabs’ most impoverished nation. During a year of turmoil, Al-Qaeda-linked militants have seized control of large swaths of southern Yemen and its provincial capital. Government operations have failed to oust the group, which is blamed for trying to blow up a US-bound airliner in 2009 and cargo planes bound for the US a year later.

Al-Qaeda has exploited the political infighting to increase greatly its presence in the country. Militants long moved undeterred in Yemen’s east, but now hold authority over territory and civilian centers, giving them a bigger toehold to win recruits and cash and plot attacks.

Saleh was seen in Washington as a committed if sometimes erratic anti-terrorism partner, and the US scored some major successes during his watch. American drones have continued targeting Al-Qaeda leaders in recent months, notably killing American-born cleric Anwar Al-Awlaki there in September. And two officials said the political fighting led the Yemeni government to authorize more American missions, describing the recent period as the first “open season” in years on Al-Qaeda leaders in the country.

The improved coordination came as Yemen could no longer even attempt to contain Al-Qaeda itself, with security collapsed across much of the country, especially in remote provinces. In Hadi, Washington sees benefits in a continuum of the status quo, provided it brings some tranquility to the capital so the government can refocus on battling terror on the ground.

A senior State Department official said there is every indication to believe that Vice President Hadi, when he in place as the president, will continue cooperation with the US The official called US-Yemeni counterterrorism work essential for the stability of the region.

Hadi will be Tuesday’s only candidate in a vote that falls short of the revolution’s democratic aspirations. But with Saleh’s fiercest loyalists and opponents agreeing to back Hadi for the next two years, the US hopes that will be time enough for democracy to take root. Over this period, American officials say they expect to see a new constitution, electoral system and parliamentary elections in Yemen.

Complicating Hadi’s job is Saleh, who has been receiving treatment in New York for injuries he sustained in an assassination attempt last year.

The Obama administration reluctantly allowed the 69-year-old leader to enter the United States, hopeful that his absence would allow Yemen to proceed with its transition process after hundreds died in clashes during the last year.

Saleh’s opponents argue that he continues to wield power behind the scenes and frustrate the efforts of Yemen’s would-be reformers, through a cadre of family members and allies who have maintained senior positions in Hadi’s government. US officials do not reject the notion entirely, but say they have tried to impress on Saleh the chance to salvage a legacy for himself as a Yemeni statesman rather than as a brutal, repressive autocrat.

Washington’s diplomacy appears to have had some success.

After weeks when Saleh’s supporters warned of possibly postponed elections or that he might return ahead of the vote, a US official said Friday that Saleh has agreed to wait until the day after Yemen’s referendum before returning. A senior Yemeni official confirmed Saleh’s participation at Hadi’s inauguration ceremony, expected Thursday, but also said he would not return ahead of the vote.

Joshua Foust, a fellow at the American Security Project and former US intelligence analyst on Yemen, said it would be preferable if Saleh did not travel to Yemen at all. Saleh’s presence alone could poison the atmosphere for reconciliation, he said. “If he were to return right now, that would be about the worst thing that could happen.”

US officials are expressing hope, however, that Hadi will be able to forge his own path — and that Saleh will allow him to. They say Hadi, Saleh’s loyal understudy during the past 17 years, is increasingly thinking and acting independently, winning legitimacy from Yemen’s divided political groupings. And, they claim, Saleh has even instructed loyalists to replace posters of his image throughout the city with Hadi’s, an acknowledgment of Hadi’s symbolic, if not necessarily actual, leadership.

That does not eliminate the danger of Hadi ending up as a stooge for a Saleh-controlled government, an arrangement that would enrage Saleh’s opponents and only lead to more turmoil. Hadi lacks a true power base, having survived under Saleh as a background figure without great sway in his native south, where people are skeptical of his fealty to the regime, and even less stature in the north. The country unified in 1990.

To strengthen Hadi’s authority, Washington is ready to provide economic assistance.

If the referendum goes ahead smoothly, and Hadi is able to assume some control over the government, the US, Yemen’s wealthy Gulf neighbors and interested countries in Europe are planning to get together for a “Friends of Yemen” meeting that would take place in March. The goal would be to coordinate international aid and incentives for Yemen’s government to continue on a path toward full democracy by 2014.