President Bush makes a good case for allowing a Dubai company to take control of key American ports. The United States badly needs foreign investment to finance its trade and budget deficits, and Treasury Secretary John Snow is absolutely right when he says, "It would send a terrible signal to friends and allies not to let this transaction go through."

But the bomb of outrage that has exploded along Pennsylvania Avenue was planted by the president himself. Since Sept. 11, he has pounded Americans with a single, scary message: we are at war, against a ruthless and deceptive enemy that will do anything -- anything -- to breach our security and destroy our way of life.

The president's campaign has been so effective that in a recent Zogby poll, 3-in-4 Americans still expect a major terrorist attack in the next two years. So why should anyone be surprised when 70 percent tell the ABC/Washington Post poll that they oppose the port deal?

Says pollster John Zogby: "That's what makes this story so ironic. I guess you can't have it both ways."

No, the president can't, not on this one. But public opinion only partly explains the fierce resistance of many lawmakers, including key Republicans. For five years Bush has treated Congress like a junior partner in the government, hiding information, refusing to testify, even deriding the validity of laws like the ban on torture.

Those tactics worked during Bush's first term, when Republican leaders swallowed their institutional pride in the name of getting the president re-elected. But not any more.

Then there are the president's budget priorities. He's poured countless billions into Iraq while domestic port safety remains underfunded. As Sen. Joe Lieberman, D-Conn., keeps pointing out, the Coast Guard estimated that it would cost $7 billion to secure U.S. ports, but Bush requested only $551 million for the next fiscal year.

Does it make sense, many Americans are asking, to spend money protecting the port of Basra instead of the port of Baltimore?

Bush also suffers from the way he's described the world since Sept. 11. In his view, countries either counter the terrorists or collaborate with them. But Dubai, the Arab emirate behind the port deal, is a study in murky contrasts.

Critics point out that Dubai helped launder money for terrorist groups, trans-shipped nuclear technology to dubious purchasers, recognized the Taliban regime in Afghanistan and supports the Arab boycott of Israel. But Dubai also provides critical docking facilities for the U.S. Navy and allows American planes to use its airfields.

In other words, Dubai is a foe at times and a friend at others. Bush is right to work with them when it suits our national interest, but he's crippled by his own "fer us or agin us" terms.

So yes, Democrats are playing politics with the port issue, seizing on the president's vulnerability and exploiting his weakness. But that's exactly what the White House has done to the Democrats for years. Team Bush detonated this bomb all by themselves.