In 2023, El Niño caused a significant drop in the water levels of Lake Gatun, leading to severe restrictions on the number of ships able to transit the Panama Canal. Despite its vast landmass, geographically isolated from the sea, the United States functions as a maritime nation, in line with Alfred Mahan’s theory of sea power, with the majority of its imports and exports relying on maritime routes. Consequently, the restrictions on Panama Canal transits that year had a substantial impact on the U.S. economy.

For Japan, an undeniable sea power surrounded by ocean and dependent on maritime logistics for 99.6% of its trade, the Panama Canal is a crucial maritime route that directly affects its economic security. This paper will examine the recent developments concerning the Panama Canal and, drawing on insights that I’ve gained from working in Washington, will analyze the impact of sea lane vulnerabilities on U.S. economic security.