Every country believes its laws apply universally. They understand that in practical terms they cannot enforce those laws overseas, but if the opportunity for enforcement arises, typically with agreements but also via other means, they all tend to go for it regardless of any consideration for territorial limits, unless a specific law says it's restricted to this or that area.

This is why, for example, the US gives itself the right to tax people in other countries. If those people happen to be Americans, the US enforces that by threatening them with this or that the moment they step back anywhere the US has enforcement means. This is also why the UK tries to enforce its censorship laws on US companies, why my country tries to enforce our censorship laws on SpaceX, and so on.

Hence, if the US considers itself capable and allowed to enforce this and that law internationally, it follows that the supreme law that governs all those more limited laws also applies internationally unless a specific point in it says otherwise (and several do, so this delimitation is in fact meaningful and coherent).