

Liberal by itself is an ambiguous term, so it’s generally best to prefix it with another word / prefix to clarify.
e.g. Neoliberal / Classical liberal - aligned to what I think parent post is saying. Implies economic right. Socially liberal - probably what the GP post means, meaning in favour of social liberties. Can be associated with economic left (usually coupled with positive protection of social liberties) or the economic right (e.g. libertarianism - usually believe government shouldn’t trample social liberties, but businesses can). Liberal is also a political party in many countries - e.g. in Australia it is a (declining, but formerly in power) right-wing party.
That said, I believe most wars are started for reasons of cronyism / crony capitalism, to distract from issues or project an image for the leader and/or for reasons of nationalism, and politicians from all sides will give an insincere pretext aligned to the politics people expect them to have.










Attacking a military ship is generally not a war crime (as defined by international law such as the Geneva treaties, Rome Statute etc…). It is an act of war (same as invasion or bombardment of another country), and is likely to see retaliation by the attacked country.
Aggression (i.e. unprovoked acts of war) is against the Charter of the United Nations, which also includes the International Court of Justice as a dispute resolution mechanism. It is up to the United Nations Security Council (at which the US has a veto) to authorise enforcement of ICJ rulings.
If a nation is acting to protect another nation facing aggression from the US, it would be legal for the attack US military ships. The reason why they wouldn’t would more be that it would likely bring counter-retaliation from the US.