On Monday, CNN's Wolf Blitzer and some others made a point of highlighting President Obama's failure to use the words "terror" or "terrorism" in his first remarks following the Boston Marathon bombings.

On Tuesday, the president changed the dynamics somewhat: "This was a heinous and cowardly act," Obama said in a brief statement he delivered in the White House press briefing room. "And given what we now know about what took place, the FBI is investigating it as an act of terrorism. Anytime bombs are used to target innocent civilians it is an act of terror."

Obama's use of the word "terror" has been much more deliberate than that of his predecessor, George W. Bush. Of course, the Bush administration saw itself waging a "global war on terror" after the Sept. 11, 2001, attacks.

In this regard, at least, Obama can be seen as the anti-Bush. He argued during his 2008 campaign that Bush invoked the term too broadly, in too black-and-white terms, and too often. Obama argued that Bush's focus on "terror" sacrificed a more effective national security.

Obama's presidency, in comparison, has been a study in caution (and former Vice President Dick Cheney has called Obama "one of our weakest presidents").

Early in his administration, Obama ditched the phrase "global war on terror" — if not the actual drone strikes against terrorist targets.

Whether it's been for political reasons, out of an abundance of caution, or some combination, Obama seems to prefer to walk, not run, to the point where he's willing to utter "terrorist."

A day after the Benghazi, Libya, attacks last September that left four Americans dead, Obama said the attackers committed "acts of terror" — but he didn't call them terrorists and was strongly criticized by Republicans for that.

Assuming Obama's Tuesday comments accurately revealed the extent of investigators' knowledge, law enforcement officials didn't yet know if they were dealing with one or more terrorists or a single "malevolent individual" like Unabomber Ted Kaczynski.

Stephen Flynn, a veteran homeland security expert and political scientist at Northeastern University in Boston, gave the president "high marks" for his statements, which on Tuesday included this:

"Boston is a tough and resilient town. So are its people. I'm supremely confident that Bostonians will pull together, take care of each other, and move forward as one proud city. And as they do, the American people will be with them every single step of the way."

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