The "home front" used to be where the fighting wasn't. In the war against terrorism, it means just the opposite the place where attacks are likely to occur.
That's why the US has a new Northern Command to coordinate military efforts to prevent a terrorist attack on home soil. But how far should this preparedness go in loosening the traditional restraints on the use of troops for domestic purposes?
In his new homeland security plan, President Bush calls for a review of federal laws that impose such restraints, notably the 1878 Posse Comitatus Act. That law was enacted to withdraw federal soldiers from Reconstruction-era law-enforcement duties in the South. But it has come to symbolize a national commitment to keep the use of military force out of the daily lives of Americans.
There have been many exceptions to that commitment over the years. National Guard troops, which are under the authority of state governors and have been used in many domestic emergencies, are exempted from the Posse Comitatus law. Presidents have sometimes used regular Army troops to quell riots. Congress altered the law to allow the armed services to take part in antinarcotics operations.
The question now is whether the antiterrorism war demands deeper changes. The president's review of the law will seek out an answer. Given the considerable resistance within the military to taking on duties that lie outside its traditional mission and training, and the flexibility under current law, a prudent course may be to keep things just as they are.
Weakening the law could undermine what has been a very clear American perception that the military exists to protect the country, never to help run it. Homeland security chief Tom Ridge has rightly noted that any expansion of the military's role into law enforcement would go "against our instincts as a country."
That doesn't mean the armed forces, in the new Northern Command, can't work closely with other federal agencies and local authorities to prevent attacks or respond to them.
Just keep the fence between military and domestic duties in good repair. The long-term interest of the country demands this.