Sen. John McCain (R-Ariz.) wants to challenge China’s hold on artificial islands in the South China Sea. (AP Photo/Brett Carlsen, File)

China’s campaign to solidify its claim over the South China Sea through artificial, militarized islands has never sat well with the United States.

But for the last few years, the U.S. Navy has avoided risking head-on confrontations to stop the construction.

Senate Armed Services Committee Chair John McCain (R-Ariz.) would like to start.

McCain laid into naval officials during a hearing Thursday for not sending ships for three years within 12 nautical miles of China’s artificial islands in the Spratly archipelago, which is the maximum international legal standard for sovereign waters.

“If you respect the 12-mile limit, that’s de facto sovereignty tacitly agreed to,” McCain told Assistant Secretary of Defense David Shear, who tried to argue the U.S. had sent ships close enough to the islands. “It seems to me, we oughtta do it.”

McCain is advocating a “freedom of navigation” operation – basically, a move to send ships within 12 miles of the islands, making good on the U.S. assumption that they are, in fact, international waters.

“The best sign of respecting the freedom of the seas is not to de facto recognize the 12-mile limit and the best way to make sure that is not recognized is to sail your ships in international waters — which it clearly is, these are artificial islands, and pass right on by,” McCain said.

But in this political environment, such a move could turn into a risky game of international seafaring chicken.

McCain’s comments come at a crucial time in U.S.-China relations, with President Xi Jinping scheduled to arrive in Washington for a Sept. 25 state visit. The U.S. has long been wary of China’s ambitions in the South China Sea. But while Washington has started to punish China for other aggressive tactics – such as tentative first steps on cyber hacking – it has avoided any moves over the islands that could, if escalated, turn into an armed standoff.

But with recent reports indicating China is building a third artificial island — reneging on a promise to pause such construction —  the calls to directly challenge China’s territorial expansion are only getting louder.

Sailing past the 12-mile mark and closer to China’s artificial islands is a strategy that has long been considered by defense officials. This summer, Defense Secretary Ashton Carter said that the U.S. will “fly, sail, and operate wherever international law allows,” a line McCain recalled during Thursday’s testimony.

Shear and U.S. Pacific Commander Admiral Harry Harris, who also testified Thursday in the hearing on maritime security in the Asia-Pacific region, agree that waters around China’s artificial islands are international territory. And they didn’t argue when McCain said the U.S. seemed comfortable when Chinese ships came within 12 nautical miles of the Aleutian Islands at the end of President Obama’s visit there earlier this month.

“We have not been asserting our rights just as forcefully,” McCain complained..

China is making a bid to assert full control over the South China Sea, and the islands are a way of both staking claim to more international waters and building a credible militarized threat to those who dare dispute them. Recently, a Chinese admiral made the  argument that the mere name of the body of water is proof that the waters are Chinese territory.

Few outside China buy that rationale. The Philippines have already brought a legal challenge under the international Law of the Sea treaty, which says flatly that “artificial islands, installations, and structures do not possess the status of islands” and “have no territorial sea of their own.” China has ratified that treaty, while the U.S. has not.

McCain’s complaints aren’t singular. He has beaten this drum before, and secured some support from the military, including Harris.

“The South China Sea is no more China’s than the Gulf of Mexico is Mexico’s,” Harris said Thursday. “We must exercise our freedom of navigation throughout the region.”

Of course, the U.S. can’t be too bellicose in its attitude toward the Asian giant, given its complex relations with the huge economic power. And the nation has been helpful to the U.S. in key ways.

China was instrumental in removing chemical weapons from Syria, combating piracy in the Horn of Africa, and is a key ally in trying to curtail North Korea’s nuclear program – though China’s influence over North Korea is waning.

“We need to develop options and act on them to deter these admittedly unconventional threats or else they will continue and grow,” McCain said.

He added that in the three years since the U.S. last sent a ship within 12 nautical miles of an artificial island, China had built up its claims – significantly.