Actually, two debates have gone missing. The first is whom to blame for the intelligence failure that let a gang of radical Islamic terrorists slip into the country, hijack jetliners, destroy the World Trade Center, damage the Pentagon, and narrowly miss attacking either the Capitol or the White House. That one was settled out of court when the 9/11 Commission achieved unanimity by blaming no one in particular in its otherwise outspoken report.

John Kerry, perhaps for sound political reasons, has deprived us of the other great debate, over whether the United States should have gone to war against Iraq. Mr. Kerry, after long evading a straight answer, finally said that he would have voted to give President Bush the war power even if he had known then what we all know now. Mr. Bush had set a trap, demanding a yes-or-no answer. The New York Times editorially joined in the demand. Maybe Mr. Kerry could have continued dodging the question. But he could hardly have renounced his vote without implying that hundreds of Americans had died in vain, that more hundreds had suffered war wounds in vain, and that still more Americans continue to risk their lives in that still-unfinished war. Howard Dean dared to call the war a mistake, and after a brief surge of popularity, lost out, much as George McGovern went down in defeat for daring to call the Vietnam War a national mistake. Most Americans really hate to be told their country has been mistaken.

The lines are now clearly drawn for a debate over the unfinished Iraq war. Mr. Bush and his supporters insist that the war rescued the Iraqi people from a tyrannical dictatorship and protected American security by preventing Saddam Hussein from acquiring weapons of mass destruction to attack the United States and its friends and peddle them to terrorist groups. They present a vision of a free, independent, democratic Iraq that will be a model for reform throughout the Middle East and the entire Arab world. Some still cling to the original warnings that Saddam Hussein had an arsenal of chemical and biological weapons and was well along toward developing nuclear weapons, and that Saddam was a secret collaborator of Osama bin Laden’s terrorist network. Mr. Bush sometimes added a further reason for going to war against Saddam: “Besides, he tried to kill my dad.”

The other side contends that United Nations sanctions and inspectors, along with U.S. bombings in 1998, had already halted Saddam’s weapons programs and that the war was a distraction from the more important war against terrorism and helped make new converts for al-Qaeda, the radical Islamic organization that engineered the 9/11 attacks and is believed to be plotting a massive new attack in this country.

Meanwhile, despite optimistic forecasts by administration leaders, the war goes on, with gradually mounting American casualties and uncounted thousands of dead and wounded Iraqis. And, according to a Wall Street Journal report, the U.S. intelligence community is debating whether the many recent arrests of terrorist suspects have crippled al-Qaeda or whether it remains strong. The article quoted senior intelligence officials as saying that new leaders have emerged, creating “al-Qaeda Central,” whose top-down command structure is sending encrypted messages to operatives in Britain and the United States and updating information on targets that were first cased years ago.

Americans deserve a thorough look at how we got into this situation. But, sad to say, there seems to be no way to cast an effective vote on such an important issue.