The impending departure of Homeland Security Secretary Janet Napolitano ought to prompt a rethinking of what is going on in Washington. Established in the wake of September 11 to better coordinate the instruments used to battle transnational terrorism, the homeland-security enterprise has been adrift for some time now. And it may not be drifting toward a good place.

Consider the talk of dismantling the department. Virtually every task undertaken by the Department of Homeland Security was performed by some federal agency before September 11. If the department were taken apart, it would go back to being a decentralized mess. That hardly ranks as progress.

Plus, it would cost a pretty penny to switch everything back. Just changing all the badges and signs would bust the spending caps set by the sequester. The pain is hardly worth the gain.

Nor is there much to fear from the creation of a massive new department. Internet rumors and tantalizing tweets aside, a center of dark, devious power the Nebraska Avenue Complex is not. Homeland Security is not buying up all our ammunition. It is not building FEMA concentration camps. It is not teaming up with the Russians for a Red Dawn rerun. Rather, the department creeps along pretty much like the rest of federal bureaucracy.

Besides, the nation actually needs a department whose number-one job is making the nation a harder target for transnational terrorism. There have been at least sixty transnational, Islamist-related terrorist plots aimed at the United States since September 11. There is a real threat out there that needs to be countered.

Furthermore, Americans may have forgotten about the danger of biological, nuclear and radiological attacks, or a catastrophic strike with an electromagnetic pulse on the U.S. homeland, but these scenarios still fill the dreams of America’s enemies.

Washington made the right decision after September 11 when it decided to create a long-term, persistent enterprise to deal with transnational terrorist threats. It has just made a lot of loopy decisions since then.

The problem is with what Washington has done since the terrible attacks on the Twin Towers and the Pentagon. It has inched the nation closer to becoming a national-security garrison state—exactly what was promised would not happen.

Since the establishment of the Republic, Americans have always been wary of centralizing domestic security under absolute federal control. Keeping public safety a local matter was a check on tyranny. If Washington did not have every power to protect us, it also meant that they did not every power to oppress us.

Deviating from the federalist model of domestic security was only thought permissible when ordered liberty itself was in danger. So, for example, when automobiles and highways made interstate crime an unmanageable problem, in stepped the G-Man to help out. Washington ratcheted up its role on the homeland in time of war, and rolled it back when the danger passed.

The post-September 11 world posed a particular challenge because the need for integrated, persistent and expansive place for the feds in the security of everyday lives was something that would likely be needed for at least a generation. To calm fears of a garrison state, Washington went out of its way to limit the function of the new enterprise to just dealing with transnational terrorism. The Department of Defense wound up flat-out claiming it did not do homeland security at all—lest Americans worry that battalions would battle terrorists from Boston to Beaumont.

Meanwhile, though the Department of Homeland Security had many missions, from policing fisheries in the North Atlantic to running down fake Gucci handbags, it insisted the homeland-security enterprise itself dealt with the department’s primary mission: stopping the next September 11.

Then the drift kicked in. After getting beat up pretty badly over the response to Hurricane Katrina, both Homeland Security and the Defense Department started to rejigger their rhetoric. For Homeland Security, disaster response went from being something the department did to a core component of protecting the homeland. The Pentagon went from providing “military assistance to civil authorities” to anticipatory response. Apparently, state and local officials could no longer be trusted to know what was needed in the wake of hurricanes and such.

Ironically, or perhaps because President Obama is so indifferent to the homeland-security mission, the drift began to look more like drunken meandering. Secretary Napolitano contributed to this, encouraging a definition of homeland security that included, well, pretty much anything the Department of Homeland Security did.

The Department of Defense got into the act as well. In its latest strategy, released this year, the Pentagon described one of its core missions in protecting the homeland as “homeland security.” In particular, the strategy reverses previous policies and stakes out an important mission for the armed forces in combating terrorism on the homeland.

Mission creep by both departments has nothing to do with dark plots to take over the nation. It is just Washington politics. Napolitano wanted a higher profile for the department on immigration reform so she could help cheerlead for an amnesty bill, so immigration policy became homeland security. She wanted a bigger role for the department for cybersecurity, so it became homeland security as well. The Defense Department was stung by criticism for its lapses at Fort Hood, so it started slapping the homeland-security label on things as well.

Congress has been just as bad. It does not take defending the homeland seriously. If it did, there would not be so many committees, subcommittees and other bodies with some jurisdiction over the department. Oversight is as dysfunctional as teenager with one hundred parents, each of whom gives the kid a different time to be home for curfew.

If Congress were serious about homeland security, it would not have gotten amnesia when Edward Snowden released information on two programs that it had specifically authorized in statute. If Congress took homeland security seriously, it would not have burdened relief for Hurricane Sandy with enough pork to trigger a heart attack—and called it vital homeland-security spending.

Of course, Washington should be concerned about incidents like hurricanes, the shooter at Fort Hood, border security, Chinese cyber warfare, earthquakes, floods and plagues of locusts. But when all these activities start become homeland security, something starts to change. Everything becomes homeland security.

All of sudden, the federal government is responsible for protecting us from all harms. Washington’s mission becomes childproofing the country. Safeguarding us from excessively large soda bottles shifts us toward the nanny-state. Will the war on obesity become the new front in the war on terror?

And when it is the responsibility of Washington to protect us from all dangers, then America will be one step away from the garrison state. It is time to put the term “homeland security” on a diet before it gobbles up the sweet land of liberty.

James Jay Carafano is vice president of defense and foreign policy studies at The Heritage Foundation.