How much did the war in Iraq contribute to the US deficit today?

I’ve heard people say Bush didn’t pay for invading Iraq. What does that mean exactly? We didn’t raise bonds like in WW2? Didn’t raise taxes to pay for bringing down Hussein? I just don’t understand the process and eager to understand. Where did the money come from then to finance the almost trillion? bucks spent there?

And how much does this amount add to our present deficit today? No one seems to talk about how the Bush war decisions years ago are still impacting the present day deficit. Is that the case really or Obama is solely to be held responsible for everything now?

If anybody could explain the movement of the war money spent in Iraq from its inception leading up to today, that would be much appreciated.