The Monroe Doctrine - isn't about spreading "liberty" - but to preserve and safeguard US national interests in it's vicinity. Especially when taking into account that ALL surrounding territory and countries were ruled by non-democratic governments aka - monarchies. The classic-natural born enemies of the USA constitution.
The war against Spain brought about US national interests towards Central-America and Asia, due to the "liberation" aka conquest of the Philippines - therefore also resulting in US interests towards Japan. Shortly afterwards US interests in regards to Africa and Europe via getting themselves involved in the Moroccan crisis. Setting up e.g. "concessions" in China. Before that, the "dubious" acquisition of the Hawaiian islands, and the legal acquisition of Alaska. In between driving out by force, or buying out French, Mexican/Spanish owned territory. The entire US history is one of non-stop expansion. - so far!
BTW, I am not blaming the USA for having done this or still doing it - every nation that has the means, has and is actively participating in this quest for global supremacy/control.
However the ones to bring it about, enforce it via military means since 1990, are simply and only the USA and NATO. - thus resulting amongst others in the Ukraine-Russia war.