IN HIS BUDGET address to parliament this month, Ugandan President Yoweri Museveni, who assumed office a quarter of a century ago, said that his country is “one of the most democratic in the world.” His response to a recent series of popular protests suggests just the opposite. Ugandans joining “walk to work” marches to protest soaring food and fuel prices have been met with excessive force, including volleys of tear gas and live bullets. A handful of people have been killed and hundreds wounded; opposition leader Kizza Besigye has been arrested repeatedly, shot in the hand and nearly blinded with gas. This shouldn’t surprise anyone, for Mr. Museveni has warned he will devour protesters “like samosas.”

The Ugandan strongman’s use of violence and his refusal to accept term limits are all too reminiscent of Arab dictators such as Egypt’s Hosni Mubarak, who, like Mr. Museveni, was supported by successive U.S. administrations despite his resistance to political liberalization. Uganda, too, appears destined for a violent upheaval unless the nation is protected from further repression by its president. President Obama and his envoys would be wise to press Mr. Museveni now for change, before protesters — whose marches have recently waned — return to the streets.

Uganda’s recent political trouble began withFebruary’s presidential election, in which Mr. Museveni won a fourth, five-year term. While the United States and international community appeared pleased with the dearth of violence during the vote, they remained relatively silent on allegations of pervasive fraud and police intimidation of voters. The Commonwealth Observer Group, which monitors election fraud globally, noted “the lack of a level playing field, the use of money and abuse of incumbency” in the election process. Rather than inviting his political rivals to participate in dialogue or committing to a term limit, Mr. Museveni has responded to opposition since the election by cracking down on journalists as well as adversaries such as Mr. Besigye.

While triggered by price increases, the protests by Ugandans also demonstrate their concern that a presidential tenure spanning 25 years has left many voiceless. Without meaningful reform, Mr. Besigye believes, the Arab Spring could morph into an African one sooner than we might expect. Like Egypt, Uganda boasts a youthful and impressionable population, half of whom are under 15. But with fewer educational and occupational opportunities than in Egypt, the potential for havoc in Uganda is arguably greater. The United States has considerable leverage with the regime, as it recently demonstrated with its opposition to an anti-gay law that was hastily withdrawn from parliament. That influence should now be used to press Mr. Museveni for restrictions on executive power and a significant expansion of space for opposition speech and assembly.