The debt rose dramatically under Obama, doubling in his eight years the entire national debt.
That $8 trillion was spent through the totality of the wars' lengths, not all under Bush's 2 terms. Still, that's a healthy chunk of change. Even so, Bush's tax cuts brought in tons of cash to the feds. Aside from war expenditures, the money was largely wasted, as usual, and not put towards the debt.
As for Bush's motives to attack Iraqi, everyone seems to have their own opinions of this. Oh he did it for oil (of which we've actually received very little... it mostly went to our military there).. he did for revenge... my take on this is that he felt he could start a democratic domino effect in the Middle East. That was erroneous thinking (20/20 hindsight), but at the time, I understood and supported it. Also, Saddam kept flagrantly violating the UN's mandates, and we had 5 other countries, three of them not friendly to the US, confirm that he had WMD programs in the works.
Obama was a socialist-progressive, hostile to Biblically-minded Christians and the State of Israel. Progressives are fascists. Bush was none of these.
I'm not under the belief that Bush was a great president. But, the country was certainly managed better than under Obama. Although, that is a low bar.