The Speaker of the House leads the House of Representatives. Think of it as the Prime Minister of a parliament with much less power. So while the Senate can technically still function, and the executive branch can still function, no one has enough support to “form a government” in the House, so no laws are able to pass, even if the Senate passes a bill. The situations are obviously very different, but the current issues with the Spanish government are a good way of understanding the Speaker drama. Maybe things will improve after the 2024 elections, but i have zero confidence with the iron grip the Republican party has over the majority of state governments.
It’s not about keeping the US navy out, it’s about having an open lane for Chinese ships to get into the Pacific. The entire Chinese cosst is boxed in by islands (and South Korea) that are staunchly pro-US. World powers have always been willing to fight in order to secure their access to foreign markets and secure trade routes.