Well, for one thing...
...there would not have been an American invasion and occupation in Iraq which has unnecessarily inflamed and motivated Islamist political power throughout the Middle East. And as for another, Bush's entire first four years was a complete abdication of American involvement in the Palestinian/Israeli conflict. Bush's strategy was to ignore the thing entirely under the naive belief that toppling Saddam Hussein would fix the Middle East. Its a terrific tragedy built on the foundation of incompetence, arrogance and ignorance.