Recent events have highlighted the importance of the freedom of the seas, a right established in antiquity, but even more important today. The capture of U.S. sailors by Iranian naval vessels last month, and China’s installation of guided missile batteries on Woody Island in disputed waters of the South China Sea, have brought the issue to the headlines, but international law is settled in the matter.

In the Iranian dust-up, the U.S. sailors had apparently entered Iranian national waters inadvertently due to an “error in navigation,” but that doesn’t alter the fact that the warships were in another country’s territory without permission. Confusion among the news outlets notwithstanding, there’s no “right to innocent passage” unless there is no way to avoid national waters, which was not the case here. The issue of the treatment of the sailors — held at gunpoint with their hands over their heads, forced to apologize, etc. — isn’t germane to the question.

Similarly, China’s creation of artificial islands far beyond its territorial waters, or placing missiles on disputed islands, raises more troubling issues, but they do not affect the law of the sea. In the case of new islands, like those created by underwater volcanoes, the nationality of the first person or persons to step foot on them has been determinative. When a country creates a new island in international waters, presumptively it owns the island. Of course, if the island lies within an economic zone — under the Law of the Sea Convention within 200 nautical miles of a country’s coastline — then that country can prevent another country from building an island there, and, by extension, can build its own islands there.

Ownership of the Paracel Islands, of which Woody Island is one, has been contested between China and Vietnam for more than a century, with China finally winning possession in the 1974 Battle of the Paracels. Clearly, military might trumps the law of the sea, but the larger issue is whether China can disrupt maritime traffic in the area. The U.S., as part of its long tradition of enforcing the law of the sea and the right of innocent passage, has sent warships within 12 nautical miles of the islands, prompting angry threats from China but no actual hostile action.

Unfortunately, the U.S. actions, backed by the might of a military that even China — at least so far — doesn’t dare provoke, are actually violations of international law in themselves, since the warships could have navigated to another position without passing through what China considers its territorial waters. The classic example of the right of innocent passage is the Bosphorus Strait. Without the right of innocent passage—by definition, the right of a vessel not intent on armed conflict to navigate through national waters when no other option exists—the Black Sea would be accessible only to Turkey, which owns both sides of the two-mile-wide channel.

Closer to home, vessels navigating the Old Bahama Channel between the Bahamas and Cuba cannot transit without entering the national waters of one or the other, since the passage south of Cayo Lobo is only twelve miles wide. In the 1980s, Cuba attempted to establish a Vessel Traffic System — ostensibly for safety of navigation but actually a provocation — in the passage, but could not enforce it due to the right of innocent passage.

So the brouhaha over China’s placement of missiles on Woody Island doesn’t reflect any change in the law of the sea or affect China’s assertion of control over the Spratleys or the Parcels. That issue may have to be resolved militarily. But in the present situation, where China is either legally or de facto in control of an island and a twelve-mile-wide area of water around it, there is no profit in entering its national waters when the law is not on our side. If the missiles on Woody Island are launched at our vessels, that’s another matter, but we should not be on the wrong side of the law.

A collection of stories from guest authors.