Truth is that economies change slowly, and politicians have much less control over it than we all like to believe.
I dont know why you are being downvoted, this is a very sensible comment. Changes in society are slow and progressive, except in very specific circumstances.
War can change things, disasters, foreign economic threats (say a trade war with a major superpower). Those can have rapid effects as well.
As always there were some short-term positive Keynesian stimulative effects by increased government spending, but a massive run-up of the deficit did increase the cost of servicing the national debt, which might otherwise have been directed into productive enterprises, rather than the wasteful Iraq war which achieved negative progress.