Michael Hirsch explains:

Behind Obama's takedown of the Qaida leader this week lies a profound discontinuity between administrations — a major strategic shift in how to deal with terrorists. From his first great public moment when, as a state senator, he called Iraq a "dumb war," Obama indicated that he thought that George W. Bush had badly misconceived the challenge of 9/11. And very quickly upon taking office as president, Obama reoriented the war back to where, in the view of many experts, it always belonged. He discarded the idea of a "global war on terror" that conflated all terror threats from al-Qaida to Hamas to Hezbollah. Obama replaced it with a covert, laserlike focus on al-Qaida and its spawn.

This reorientation was part of Obama's reset of America's relations with the world. Bush, having gradually expanded his definition of the war to include all Islamic "extremists," had condemned the United States to a kind of permanent war, one that Americans had to fight all but alone because no one else agreed on such a broadly defined enemy. (Hez¬bollah and Hamas, for example, arguably had legitimate political aims that al-Qaida did not, which is one reason they distanced themselves from bin Laden.) In Obama's view, only by focusing narrowly on true transnational terrorism, and winning back all of the natural allies that the United States had lost over the previous decade, could he achieve America's goal of uniting the world around the goal of extinguishing al-Qaida.

This is quite true: Bush and Obama perceive the terrorist threat in very different ways.  

But only one of those visions makes sense and has yielded actual results.

Sadly, the perception that Republicans are better than Democrats at national defense will probably continue because… well, because Republicans are better at taking victory laps than Democrats.  Bush was flying on to carrier decks with "Mission Accomplished" banners, even when no mission was accomplished.

And is Obama taking a victory lap?  No.  He's laying wreaths and commemorating the fallen from 9/11.  Oh, well.