Before envisioning dramatic change, the Roman emperor Augustus is said to have warned, "Make haste slowly." The reformer Augustus was eager for radical social transformation. But he also knew he had to deal with generations of Roman tradition and habits.

President Obama should heed Augustus' advice before he plans any more doomed top-to-bottom change.

Take his stalled health care reforms. Rather than trying to turn a largely private system all at once into a huge state-controlled and regulated industry at a time of historic deficits, he would have been better off advocating incremental changes.

Tort reform, for example, would reduce frivolous lawsuits that drive up medical expenses. Or health insurers could be allowed to compete across state lines. Tax credits and grants could focus on the uninsured. The costs of such changes would have been marginal, the savings large.

Instead, a 1,000-plus-page health care bill had so many regulations that not even its congressional authors could explain all the details or predict their effects. And so President Obama's massive overhaul looks like it will meet the same fate as Bill Clinton's doomed 1993 "comprehensive" effort to remake American health care.

Obama also promised a remake of the war on terror — including changing even its name to "overseas contingency operations." He campaigned on ending military tribunals, renditions and the Guantanamo Bay detention center. The Patriot Act and Predator drones were supposed to be trimmed back.

Candidate Obama wanted combat troops to leave Iraq in March 2008 and declared the surge there a failure.

That comprehensive "reset" strategy was also quietly dropped. Obama has instead continued almost all the old Bush anti-terrorism protocols. Despite campaign talk of quickly getting out of Iraq and criticizing our supposed terrorizing of civilians in Afghanistan, Obama follows most Bush policies in Afghanistan and Iraq. Loud promises to close Guantanamo, investigate former CIA interrogators and try terrorists like Khalid Sheikh Mohammed in New York so far have not happened — and probably won't.

George Bush failed with massive immigration legislation in 2008. Bush wanted to address all at once every problem from closing the border and guest workers to amnesty and earned citizenship.

Instead, far better would be a more modest effort to just close the border — and worry about the other problems later. That could be done fairly easily through enforcing existing employer sanctions and finishing the border fence.

In fact, very few presidents succeed in "comprehensive" reform. Bush — pointing to his mandate after the 2004 victory over John Kerry — vowed to change public Social Security into a semi-private enterprise. It was a radical plan in which younger workers could open their own private investment accounts.

But just like Obama's effort to remake health care, the more Bush campaigned across the country for comprehensive Social Security reform, the more the public seemed to be opposed. Far easier would have been raising the retirement age by a year or two.

Why do such comprehensive efforts usually fail?

Comprehensive reform often involves new laws, more money and additional bureaucrats. Yet almost every problem facing America arises from too much federal spending and borrowing — not too little government.

Finally, offering "comprehensive" reform usually means years of arguing and horse-trading among pressure groups to get anything done. By the time all the special interests are appeased or bought off, the resulting elephantine legislation typically looks nothing like what was intended.

In short, big-government medicine usually doesn't work on big-government sickness. If President Obama wants "comprehensive" change, it would be better simply not to spend any more money we don't have — another lesson from Augustus, who put financial reform and budgetary sanity above everything else.