The US may have just inadvertently bolstered China's claims in the South China Sea

On October 27 the US Navy conducted a "freedom of navigation" (FON) operation through the South China Sea. The move, which came after months of deliberations among the White House and the Pentagon, was meant to assert that the US did not recognize Beijing's extensive maritime claims in the region.

The US sent the USS Lassen within 12 nautical miles of China's artificially constructed Subi Reef in the Spratly Islands, along with an accompaniment of two surveillance aircraft.

But the message that the Pentagon hoped to send to China through the FON may have been drastically undercut by pressure from the White House, Josh Rogin reports for Bloomberg View.

Instead of having carrying out an FON operation, it now appears that the Pentagon's actions actually fell under a different legal category. The US operation was aimed at establishing "innocent passage," and not freedom of navigation in the area.

There's a crucial difference between these two concepts. According to the Center for Strategic and International Studies (CSIS), FON operations "are legal exercises to reinforce the United States' - and in this case the overwhelming majority of the international community's - interpretations of international maritime law."

These operations have a confrontational purpose to them. As the CSIS report notes, FON operations are "intended to challenge maritime claims that the United States considers excessive under international law."

The FON operation was meant to feature a US Navy vessel sailing within 12 miles of China's man-made islands in the South China Sea while being followed by US surveillance planes. That distance was meant to challenge China's claim of having nautical territory that extends 12 miles out from any of its territories in the South China Sea.

But as Rogin reports, the White House insisted that the Pentagon refrain from carrying out more robust aspects of the FON operation. The Lassen was not allowed to "turn on sensors or fly its helicopters, actions that military experts say would have made clearer that the US was conducting a freedom of navigation operation," according to Rogin.

Euan Graham also reports for The National Interest that while carrying out the operation, the surveillance planes trailing the US ship stayed outside of China's declared 12-mile nautical boundary. This less-confrontational moves indicates that the entire operation was not actually a FON, but actually what's referred to in maritime law as "innocent passage."

Innocent passage does not carry nearly the same weight as a FON. Again, according to CSIS, "[i]nnocent passage under international law is the right of civilian and military vessels to peacefully sail through the territorial waters of a foreign country as long as they do not perform activities not directly related to transit (including military exercises and intelligence gathering)."

As such, the US's actions are aimed more at establishing innocent passage in the area than at establishing freedom of navigation. And, if China does indeed regard the action as innocent passage, than the entire exercise may end up bolstering Beijing's view that its maritime claims are acceptable.

Graham notes that the "demonstration value could be thrown dangerously into reverse if Beijing drew the conclusion that the conduct of innocent passage amounts to customary acceptance of a de jure territorial sea around Subi Reef and other submerged features or low-tide elevations under China's control in the Spratlys."

If that the case, the White House's pressure on the Pentagon may have undercut the military's ability to send a strong message about the US's position on China's claims in the area, with the result that Beijing won't be convinced to change its behavior in the disputed region.

As CSIS notes, the US has promised future FON operations throughout the South China Sea. The Obama administration has also urged regional allies to conduct their own FON operations as well.