Congress begins debate this week on President Bush’s proposal to create a Cabinet-level Department of Homeland Security. This is an enormous undertaking – at last count, some 180 different agencies, bureaus and offices will be involved, more than a dozen House and Senate committees have jurisdiction – and the finished product would represent the greatest federal makeover since World War II.

It is an important undertaking. The security and intelligence lapses that led up to Sept. 11 and that have occurred since are unacceptable. Reorganizing government agencies is not glamorous or easy, but the stakes here are so high many members of Congress view this particular effort as the most important and historic work they will do in their public lives.

Through the coming turf battles and amid the pressure individual agency, bureau and office heads will exert to keep their own fiefdoms intact, Congress would do well to remain focused on the target – preserving civil liberties while actually improving security.

Not, as has often been the case since Sept. 11, by trampling – or at least badly bruising – civil liberties while the lapses continue. Not by mistaking hassles with no purpose, intrusive searches with no cause, probing questions with no point and long lines with no end for security.

Certainly not, as occurred this last weekend, by turning away members of a Canadian girls’ softball team at the border. The team of 15-and 16-year-olds, the Kelowna Heat from south-central British Columbia, was set to play at a tournament in Spokane, Wash. Most of the girls, and their families, entered the United States without incident at two crossings in the region. Three, however, had the bad luck to choose the Cascade crossing and were denied entry.

The reason? Lack of proper identification. They had the same documentation – school photo IDs and government health insurance cards – as teammates who got across elsewhere, as thousands of Canadians use every day. They had notarized letters attesting to the reason for their visit. One girl – 15, the Heat’s star pitcher – was listed on her father’s passport and her father was driving the car. They had their uniforms and equipment with them as evidence of their intent to play ball. They offered to have tournament officials in Spokane vouch for them. Not good enough for the defenders of America’s security on duty.

They asked to speak to the guards’ supervisor, in the belief that a higher-up would take a more flexible approach, Instead, he turned out to be more rigid, not only denying the girls and their families entry, but also warning them they would be banned from the United States for life if they tried one of the other nearby crossings. So, three players short, the Kelowna Heat lost in a forfeit.

It’s a minor incident, yet quite similar to countless other absurdities and outrages that have taken place when inane bluster is mistaken for real security. It’s the sort of cautionary story Congress should keep in mind as it begins this work.