Much has been written about the George W. Bush administration’s attitude toward promoting democracy. President Bush often spoke of ending tyranny in the world and the unselfish, humanitarian benefits he hoped to achieve. But he never argued, in public or private, that America should go to war in order to spread democracy.

Neoconservatives, including myself, were accused of wanting to spread democracy by the sword. But I saw no evidence of that. We supported war in Iraq to defend America against threats. The Saddam Hussein regime was posing serious dangers, as the United Nations containment strategy for Iraq deteriorated.

The war would open a way for a new democracy to arise, as it did with Germany, Italy, and Japan after World War II. If democracy grew successfully, America, as well as the people of Iraq, would benefit.

Democracy’s progress around the globe in the 20th century contributed to America’s security and freedom. The experience of that century suggests that war is less likely between democratic states than between states that are not democratic.

Moreover, history shows that our civil liberties are safer in a world where freedom and democracy are spreading rather than shrinking. When Americans sense that enemies are gaining ground abroad, we tend to curtail liberty at home. Fears about anarchism and Bolshevism after World War I gave rise to anti-sedition legislation and the Palmer raids.

When both Hitler and Stalin rode high in the months after the Nazi-Soviet Pact of 1939, Congress passed the Smith Act, which made it a crime to advocate the violent overthrow of the American government. And the extension of Communist rule to Eastern Europe and elsewhere after World War II helped give rise to McCarthyism.

Despite the formidable difficulties of promoting democracy abroad, I disagreed with those who said it is impossible to build democracy in the Arab or Muslim worlds. There are quite a few examples of democracy’s growth, over time, in lands that hardly seemed rich with democratic potential. Consider what someone with a so-called “realist” outlook might have said in 1946, about Germany and Japan, with their autocratic politics and militaristic cultures, becoming democratic, stable, and largely pacifistic within a few decades.

America has much to gain from democratic political reform in the Muslim world, just as we had much to gain from such reform in Germany and Japan.

“Realists” theorize that American interests are unaffected by whether other countries in the world have totalitarian governments and hostile philosophies. That theory is hard to square with recent history. When communist ideology collapsed in the Soviet empire in the late 1980s, almost all the newly independent states shed that ideology — and they ceased to be enemies of America. Within a few years, Poland, Hungary, the Czech Republic, and seven other countries, including the Baltic republics of the Soviet Union became our NATO allies.

To assume, on the basis of realist theory, that America had no interest in whether Saddam’s regime would be replaced by a democratic government or a Baathist dictatorship would not have been pragmatic policy making.

It is wrong for critics to accuse the Bush administration of having overthrown Saddam for the purpose of democratizing the Arab world. Once President Bush decided — for security reasons — that Saddam had to be removed from power, the next decision was whether America should try to help the Iraqis build democratic institutions. Mr. Bush concluded that the interests and principles of our country required him to try to promote democracy.

Secretary of Defense Rumsfeld, his deputy Paul Wolfowitz, and I often discussed the importance of balancing U.S. interests with our other interests in promoting democracy abroad. We sometimes disagreed on how much weight to give the various interests, but none of us insisted that the promotion of democracy should take precedence over all other American interests.

Commentators from the “realist” school of thought accused us of being ideological rather than pragmatic on this issue. But our approach was pragmatic and realistic.

The Bush administration did not go to war in order to spread democracy. But we saw that the war would create an opportunity to promote democracy in the Middle East. And we understood the U.S. interest in capitalizing on that opportunity, if possible.

Recent news from Iraq gives some hope that democratic institutions may be gaining strength and capability there — the government there is sharing oil revenues and passing legislation and Iraq’s security forces are operating more boldly and skillfully against Shiite militias as well as Sunni insurgents.

If government institutions grow and stabilize in Iraq, they can help counter ideological support for terrorist extremism and serve American interests in a more peaceful and prosperous Middle East.

Mr. Feith was under secretary of defense for policy between July 2001 and August 2005. This article is adapted from his new memoir, “War and Decision: Inside the Pentagon at the Dawn of the War on Terrorism.”