Since the world was covered mostly by water, only a strong navy would enable a nation to "project" it's military might (armies) across the globe.
If a nation didn't have a strong navy, they could...
In 1883 the US Navy was directed to transition from a wooden ship navy to a iron/steel ship navy. The rest of the world's navies were doing the same thing. In 1890 USN Capt. Mahan published a book...