President Bush informed the nation, during a press conference, he might seek to use the U.S. military to quarantine parts of the nation if there is a serious outbreak of the deadly avian flu that has killed millions of chickens and 60-some people in Southeast Asia.

That's the second time Mr. Bush has expressed a desire to use the military for local policing. The first was in the wake of Hurricane Katrina. The Posse Comitatus Act (18 U.S.C. 1385) generally prohibits federal military personnel and National Guard units under federal authority from law enforcement within the United States, except where expressly authorized by the U.S. Constitution or Congress.

Enacted during Reconstruction, the purpose of the Posse Comitatus Act was to severely limit federal use of the military for local law enforcement. Would Americans tolerate such a gigantic leap in the federalizing law enforcement?

I'm guessing the answer is yes. In the name of safety, we've undergone decades of softening up to accept just about any government edict that our predecessors would have found offensive. Let's look at some of it.

The antismoking movement might be the beginning of the softening-up. They started calling for reasonable actions like no-smoking sections on airplanes. Then it progressed to no smoking on airplanes at all, then private establishments such as restaurants and businesses. Emboldened by smokers' timidity, some jurisdictions have ordinances banning smoking outdoors, such as at beachesand parks.

Then there are seatbelt and helmet laws, sometimes zealously enforced by using night-vision goggles. And Americans accept government edicts on where their children may ride in their cars. Americans sheepishly accepted all sorts of Transportation Security Administration nonsense. In the name of security, we've allowed fingernail clippers, eyeglass screwdrivers and toy soldiers to be taken from us prior to boarding a plane.

We've accepted federal intrusion in our financial privacy through the Bank Secrecy Act. Rep. Ron Paul, Texas Republican, says, "More than 99.999 percent of those [who] had their privacy invaded were law-abiding citizens going about their own personal financial business."

Most recently there's the U.S. Supreme Court Kelo decision, in which the court held local governments can take a private home and turn it over to another private party. Politicians have learned and become comfortable that Americans now will docilely accept about any legalized restraint on their behavior.

You say, "Hey, Williams, but it's the law." In the late-1700s, the British Parliament enacted the Sugar Act, the Stamp Act and the Townshend Acts and imposed other grievances enumerated in our Declaration of Independence.

I'm happy we didn't have today's Americans around at the time to bow before King George III and say, "It's the law."

Respectful of the Posse Comitatus Act, Mr. Bush has suggested he'll ask Congress to amend the law to allow for using the U.S. military to enforce regional quarantines. Whether Congress amends the law or not, Mr. Bush has no constitutional authority to deploy military troops across the land. Why?

The U.S. Constitution's Article IV, Section 4 reads, "The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened), against domestic Violence." Coupled with the Tenth Amendment, "The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people," this means short of an insurrection, the U.S. military must be invited by a state legislature or executive. Any federal law that violates these constitutional provisions is null and void and can only be enforced through fear, intimidation and brute military force.

Walter E. Williams is a nationally syndicated columnist.