This is actually, in any jurisdiction, what I take the most issues with: presidential systems headed by practically very soon-to-be-dead men. I have changed with age; surely the flexibility, inventiveness, and power an individual can constructively wield on his own is highly impacteded by age. Half-dead men should retire, not take office, or consult, at the utmost.

This fact is more illustrative of whatever divide the US is under than anything else. It's generational conflict. And face it, the American president is not of any generation that has yet to build their future. A waxy president who is full of thought and reflection might not be the wise emperor who is still mighty enough to control the backstabbing theatre that is politics.

Effectively, in terms of foreign policy, I think nothing, absolutely nothing will change. From a non-American point of view, Trump did nothing too different from what Clinton would have done, and a Biden will not do something too different from what a Trump would do. Or do what he is told, for that matter.