In a landmark decision on June 12, the Supreme Court ruled 5-4 that the government had no right to imprison suspected terrorists in Guantanamo Bay without the right to a fair trial.

The decision reversed a radical piece of legislation passed in 2006 called the Military Commissions Act, which declared that “”no court, justice or judge”” had jurisdiction over the internment camp at Guantanamo Bay, despite the fact that the United States has had control of the bay since 1903, making it as much “”American soil”” as Pearl Harbor was in 1941.

The Bush administration’s contention that it could do whatever it wanted in Guantanamo Bay, including imprisoning people without trial, was without merit, said Justice Anthony Kennedy, writing for the majority, because it presented a dangerous precedent for the country. To uphold this argument, Kennedy wrote, was as good as declaring that the government possessed the right “”to switch the Constitution on or off at will.””

In a word, despite the divided nature of the decision, the Court stood up for the rule of law and order and defended a political right as old as the Magna Carta, an eminently conservative value. Hence columnist George Will, a conservative, praised the decision because it marked “”a boundary against government’s otherwise boundless power to detain people indefinitely.””

Less scrupled “”conservatives,”” however, reacted with such contempt for law and order that one wondered whether they merit the label at all.

“”One of the worst decisions in the history of this country,”” declared John McCain, who used to say we should close the Guantanamo prison. A “”policy of delusion”” and a “”Sept. 10 mindset,”” clucked McCain’s top foreign policy adviser, Randy Scheunemann. Bill Kristol suggested that President Bush should take a cue from old Andrew Jackson: “”Justice Kennedy has made his decision. Let him enforce it.””

It would be futile to parse remarks like this for the quality of their argument. There is none. All that the attacks on the Court’s decision rest on is the premise that the president of the United States has the right to do whatever he wants, as long as he can justify it by referring to national security.

Indeed, John Yoo, one of the chief architects of the Bush administration’s legal apologies for its extra-legal activities, protested the ruling by arguing in the Wall Street Journal that the Supreme Court had no right to rule on any question concerning war and accused the Court majority of a “”power grab.””

Yoo and his ilk have been fond of defending the administration’s illegal conduct of the War on Terror by arguing that President Lincoln suspended habeas corpus during the Civil War. Lincoln, however, did not violate the law because the Constitution permits habeas corpus to be suspended “”in cases of rebellion or invasion.”” Since the country is neither being attacked by rebels nor is it under invasion by a foreign army, the right of habeas corpus remains intact wherever the United States has jurisdiction, and that includes Guantanamo Bay.

It would be easy to dismiss all of this as something that has nothing to do with most of us. That would be wrong. Implicit in the Bush argument is its logical extension: If noncitizens can be imprisoned without trial in the name of “”national security,”” a sufficiently alarming crisis might well serve as an excuse to imprison citizens.

If America ever suffers another terrorist attack – something that doesn’t seem unlikely, given the Bush administration’s blatant lack of interest in capturing the head of al-Qaeda – we may well see the government’s “”boundless power,”” painstakingly concentrated in the executive’s hands through a stack of legislation and executive orders in the last six years, used against the rest of us.

Since the administration has sought, through timely use of “”alerts”” and pseudo-crises and the ever-hanging threat of another attack, to turn as much of the population as it can into a hysterical mob, it is unlikely that there will be many sane voices heard in those days. Let’s hope that the Supreme Court’s long-overdue decision will stand as a rebuke to undemocratic government even then.