With a military as big and armed as the US, you can absolutely argue that our binge internal politics are actually worth taking into account for these sort of things. The fact that seemingly half of the US population voted for it (whether they were actually for it, or were just voting not Democrat to “own the libs” is another conversation) is fucking terrifying.
The reason I would say that Trump is worse than Dubya is because of the potential and horrific shitshow that could happen if the US became more like Russia or China. To help put it into perspective, imagine if Putin was in charge of the US army. It’s not too crazy of a stretch to say that he would probably invade all of his small surrounding neighbors and absorb them as Russian territories or make them become part of Russia itself. Take this example a step further - he has access to the US arsenal of nukes. How long would it be until he would fire nukes at other nations and invade them?
That’s not to say Dubya is better - like I said, starting a 20-year war for oil but masking it behind “removing WMDs” and “God told me to do it”, wasting lives pointlessly for greed is fucking disgusting. But it would legitimately pale in comparison to the damage somebody like Trump being in charge of a fascist US can and would do to the world for years to come.