Russ Read on April 25, 2016 at The Daily Caller News Foundation

The Department of Defense’s Freedom of Navigation (FoN) report for 2015 shows that adversaries restricting access to key waterways and airspace poses a direct challenge to both the U.S. and international law.

Among the 13 top violators mentioned in the report are countries like China and Iran, but there also some unexpected additions that control key sea lanes like the Phillipines, Indonesia and Nicaragua. The range of violations spans from restrictions on the routine passage of warships to international navigation through excessive territorial sea claims.

According to the DoD, the FoN program exists to ensure the “rights, freedoms, and lawful uses of the sea and airspace available to all nations under international law.” To accomplish this task, U.S. forces “challenge excessive claims asserted not only by potential adversaries and competitors, but also by allies, partners, and other nations.”

The program serves a crucial purpose in upholding the rights and international laws afforded by the Law of the Sea Convention. Typically, a country is permitted to establish rules for navigation of sea and air up to 12 nautical miles from the end of its landmass, but the convention sets up the rule of freedom of navigation, which essentially lets any ship enter territorial waters peacefully. Maintaining respect for this rule globally is crucial to international maritime trade, transportation and the global economy itself.

Given recent disputes over China’s militarization of the South China sea, it is not surprising that it was the worst violator of international norms in 2015. Among its listed transgressions are “excessive straight baselines,” which define the territorial waters of a country’s coast if it is especially indented or has several islands off its coast.

Additionally, China is accused of overly strict control over aircraft flying in certain zones around the country. Of particular note was a law that makes it illegal for any foreign country to survey what is called the Exclusive Economic Zone (EEZ), the area 200 nautical miles from a country’s coastline in which it has exclusive rights for various activities such as energy production. China has also been accused of requiring “prior permission” for foreign military ships to cross through its territorial waters, which could be considered a violation of the convention.

Iran’s violations are not as wide-spread as those of the Chinese, but they are highly concentrated in the key Strait of Hormuz waterway. The Strait of Hormuz is crucial to U.S. and international interests as 18% of the world’s oil supply depends on it. The U.S. Energy Information Administration has referred to it as “the world’s most important chokepoint.” In the last year, Iranian naval forces have harassed civilian shipping, challenged foreign military ships and apprehended a group of U.S. Navy sailors who had drifted into Iranian waters.

Included in the release of the report, the DoD noted that it “transparently demonstrate[s] the U.S. non-acquiescence to excessive maritime claims, while still protecting the operational security of U.S. military forces.”

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