THE PARADOX OF Meles Zenawi, the prime minister of Ethiopia who died Monday at 57, was that he might have been so much more. A friend who knew him for two decades recalled that he was sharp, articulate, well-read and a patient listener. When President Bill Clinton visited Africa in 1998, he singled out Mr. Meles as an example of the African renaissance, a new generation of leaders.

Beyond a doubt, Mr. Meles, who ruled Ethiopia for 21 years, managed to elevate the nation of 75 million people into a regional economic and political power. Although most of the population is still desperately poor, Ethiopia has attracted foreign investment and built a middle class with an authoritarian, state-driven capitalism based loosely on China’s model.

Mr. Meles, who quit medical school to join the guerrilla force that toppled the dictator Mengistu Haile Mariam in 1991, put Ethiopia on the front lines of the war on terrorism, dispatching troops to Somalia against the radical Islamic Courts movement linked to al-Qaeda. He also played a key role in attempting to bridge the gap between warring Sudan and South Sudan, and under his leadership, Ethi­o­pia has been an important U.S. ally, receiving hundreds of millions of dollars in aid.

But Mr. Meles’s promise as a leader was marred by contempt for the rights of his people. When internal discontent boiled up during the 2005 general election, international observers witnessed extensive vote-rigging. Demonstrations turned violent. The government cracked down on the protests, and at least 193 people were killed, thousands arrested and dozens of opposition activists and journalists arrested and charged with treason. When a friend asked Mr. Meles after these events how he could oversee the shooting of innocent people in the streets, the prime minister shook his head and replied, “There was a serious threat. The system needed to be protected.”

Mr. Meles’s desire to protect his political “system” grew more and more repressive. Under the guise of national security, the parliament passed legislation between 2007 and 2009 to stifile dissent. According to Amnesty International, an anti-terrorism law “effectively criminalizes freedom of expression.” The State Department’s 2011 human rights report notes that the government arrested more than 100 people between March and September, including opposition political figures, activists, journalists, and bloggers.

For decades, the United States has struggled with valuable allies who were intolerant dictators at home. The Cold War often provided a reason to look the other way. So did the need for oil imports. Over the last decade, the war on terrorism offered a similar pretext. The world is full of trade-offs and tough choices. But the passing of Mr. Meles ought to underscore once again that, no matter what the imperative for embracing a tyrant, it is essential and healthy to declare: Democracy and human rights are universal values, not to be forgotten with the next aid check.