I don't mean to imply that Bush was part of the planning of these recent terrorist actions, but that, like the aftermath of Hurricane Katrina, Bush's incompetence made things worse.
During the campaign season, Barack Obama was criticized for signaling a willingness to get tough with Pakistan, for saying that he would re-focus attention on Afghanistan and Pakistan rather than stay gallivanting in Iraq. He called for redeploying troops back into the places where al-Qaeda was known to be active to finish the job" rather than continuing Bush's ill-advised Baghdad-bound crusade.
Given that the attacks appear to have ties to Pakistani militants, it makes Obama seem prescient and not naive, as Hillary Clinton tried to paint him during the primary season. What would have happened if Bush had Obama's vision and concentrated on the real terrorists. Perhaps nothing changes, but perhaps Mumbai never happens. The stakes are potentially high. Juan Cole writes at Informed Comment:
If the Pakistani government does not give up this covert terrorist campaign in Kashmir and does not stop coddling the radical vigilantes who go off to fight there, South Asian terrorism will grow as a problem and very possibly provoke the world's first nuclear war (possible death toll: 20 million).
As it is, we can never know for sure how much Bush's negligence towards foreign policy and international security has made things worse. But we can wonder.