Navy men in DC Guam base

The video discusses the global spread of military concerns and highlights the strategic importance of Guam in the US military's plan to maintain peace in the Western Hemisphere. Despite its significance, Guam is currently inadequate as a naval base, with limited defenses consisting mainly of a small group of US Marines tasked with policing the island.

Why is the development of Guam considered essential in the U.S. plan?

What are the limitations of Guam's defenses as mentioned in the text?