B) Extremely debatable. There's a lot we could do with 800B that would have a much more tangible impact on the average American.
If it's in our interest, it's in the worlds interest as well. Something tells me it wouldn't be too long before the UN had a maritime task force capable of defending shipping.
To put this into context, the United States has 11 aircraft carriers, 38 overseas bases, 130,000 troops overseas and nukes [1]. Turkey has 1, 12 and 60,000, respectively; Russia 1, 10 and 50,000 (exempting Ukraine, I think).
You have to go from China to Australia--through India, Japan, France, Italy and the U.K.--to get to America's aircraft carrier fleet. U.K., Turkey and France for bases (this one is plausible). And none of this counts the massive logistics reserve the U.S. military has compared to the world.
America has built and funded a military designed to check global hegemony. It doesn't produce it, even if our policymakers sometimes pretend it does. But it prevents a global hegemony from emerging, with regional hegemons kept from dominating their neighbors. In general, it is difficult to read history without concluding this is the right approach. It's basically antitrust as geopolitics. [1] https://en.wikipedia.org/wiki/Power_projection#Power_project...
Riyadh--specifically, MBS--is also being petulant and immature in taking for granted American support. There is remarkable symmetry between Netanyahu and MBS in this respect, e.g. the former trashing Israel's formerly bipartisan image by allying with the GOP under Obama and Trump.
a) it's one of the few countries with global force projection capability
b) it's in both its long and/or short term interest to do so
Today, the US under Biden is pretty selective about intervention. For example, it isn't intervening on the the behalf of the Saudis anymore as their oil isn't as important to the US as it used to be.