A record was set at Monday’s Boston Marathon, though not one that anybody would celebrate: The bombing of the event has the sad distinction of having the highest toll of those killed and injured of any terrorist attack on American soil since 9/11.

Three people were killed and more than 170 were wounded after two explosive devices full of metal, nails and ball bearings ripped through the crowd near the marathon’s finish line.

As emotions run high in the wake of this tragedy, it’s critical to maintain perspective and resist the desire to prematurely attribute blame or call for new government powers.

Thankfully, terrorist attacks have become rare in the United States.Radical groups carried out 1,357 attacks here in the 1970s, criminologist Gary LaFree told The New York Times — a figure that fell in later decades because of the arrests of group members and the collapse of the Soviet Union, which had backed some violent causes.

Sept. 11, as horrific as it was, was an anomaly; about 40 percent fewer attacks took place in the U.S. in the decade after 9/11 than in the decade before it.

Tuesday, after calling the Boston bombings “an act of terrorism,” President Obama wisely emphasized, “What we don’t yet know, however, is who carried out this attack, or why.”

Indeed, early reports aren’t always accurate. A Jordanian-American man from Oklahoma City was held in the 1995 bombing there. A security guard who spotted a pipe bomb at the 1996 Atlanta Olympics became the focus of speculation that he’d set off that bomb. Neither man, it turned out, had anything to do with those attacks.

While President Obama merits praise for implicitly calling for a stop to finger-pointing in the Boston blast, his administration has made power grabs after similiar incidents and should be closely watched lest it attempt similar moves this time.

After a man tried to blow up a plane over Detroit in 2009, the Obama administration created a policy giving the U.S. government the right to arrest terrorism suspects and not provide them with Miranda warnings before questioning them — one in a series of decisions in which President Obama has kept intact or expanded Bush-era civil liberties policies criticized by candidate Barack Obama.

Patriots Day marks the anniversary of the first battles of the war that gave rise to democracy as we know it. Democracy is strengthened when we honor the freedoms that make us a model worldwide; it is eroded when we exploit fear in order to roll back these same freedoms.