JAPAN'S protest to China that its warships recently locked their weapons-control radars onto a Japanese navy destroyer and a military helicopter raises disturbing questions.
In these two separate incidents, not far from the bitterly disputed Senkaku or Diaoyu Islands in the East China Sea, one question is the extent to which effective civilian control is being exercised over China's armed forces.
If China's military, or rogue ultra-nationalist officers, are calling the shots in a crisis that potentially involves not just Japan but also its ally, the United States, it could trigger a wider war with consequences that would destabilise the Asia-Pacific region.
Japan's Defence Minister Itsunori Onodera warned China last Thursday that it may have violated the United Nations Charter by threatening force against Japan, which administers the uninhabited Senkakus in the teeth of rival ownerships claims from China and Taiwan.
In an apparent sign of escalating militarisation in the dispute, the Chinese navy's use of weapons-targeting radar last month was considered highly threatening by Japanese military commanders because it could signal preparations for a missile attack.
A defence ministry official in Tokyo said that in both radar incidents, Japanese commanders took "standard evasive manoeuvres", like changing course, but did not engage their weapons systems.
The Japanese destroyer was targeted "for several minutes" on Jan 30 by a Chinese frigate about 3km away, the official said, while a ship-based Japanese military helicopter was locked onto 11 days earlier.
The Jan 30 incident occurred in international waters about 100km north of the disputed islands.
Since Japan nationalised the islands last September, China has taken increasingly intense measures to challenge Tokyo's control, with Chinese jet fighters and warships replacing unarmed coast guard-type planes and vessels in several of the latest encounters.
A key question is who is authorising the Chinese build-up and the actions taken that could lead to an exchange of fire?
China's new leader Xi Jinping, who has close ties to the military, may have answered the build-up part of the question, but the source of the radar lock-on order has yet to be clarified.
A spokesman for China's foreign ministry said last Thursday that "competent Chinese authorities" were conducting "sincere and serious" investigations into the case.
Japan's Asahi newspaper reported on Feb 4 that China's response to the Senkaku dispute was now under the direct command and coordination of a top- level task force of the ruling Communist Party of China (CPC), which Mr Xi leads as general secretary.
It seems highly unlikely that the captains of the two different Chinese frigates involved in the separate radar-targeting incidents would have given the orders on their own.
In China's military organisation, including the navy, each senior commander is flanked by a political officer who is supposed to ensure that the interests and policy of the party are acted upon.
Indeed, the CPC's 18th Congress last November that elevated Mr Xi to party chief and China's president-designate sought to tighten party (which in China means civilian) control over the armed forces.
Among other things, the Congress named Mr Xi as the new chairman of China's Central Military Commission overseeing military operations. His two predecessors had to wait for two years for the top job on the commission.
Since then, Mr Xi has made well-publicised visits to units of all five major service branches - army, navy, air force, armed police and the body responsible for missiles and nuclear weapons.
On those visits, one of the themes he emphasised was the need to be combat-ready. But another theme he repeatedly underscored was for the military to be absolutely loyal to the CPC and accept its leadership.
As China's defence spending has risen rapidly to become the world's second-biggest (though still well behind the US'), its armed forces have acquired an increasingly powerful array of weapons and equipment.
These give the military a more direct interest in the conduct and enforcement of foreign and security policy, including China's sweeping claims to ownership and control of disputed maritime zones in the East and South China seas that the armed forces consider to be vital for the country's strategic interests and territorial integrity.
Some of China's most strident hawks are serving or retired military officers. While they do not claim to speak for the leadership, they are given licence to speak out on some issues at certain times.
Air force Colonel Dai Xu is prominent among those calling for military action to secure China's offshore claims.
With China challenging Japan in the East China Sea, and US ally the Philippines, and Vietnam in the South China Sea, he has argued that a short, decisive war, like China's 1962 border clash with India, would return maritime territory and resources stolen by Japan and the colonial masters of South-east Asian countries when China was weak, and deliver long-term peace.
Colonel Dai, a researcher at Beijing University's China Centre for Strategic Studies, asserts that the US, despite its Asian alliances, would not risk war with China over these territorial disputes.
"Since we have decided that the US is bluffing in the East China Sea, we should take this opportunity to respond to these empty provocations with something real," he wrote in a commentary last August in the Global Times, an often nationalistic tabloid published by the CPC's mouthpiece, the People's Daily.
"This includes Vietnam, the Philippines and Japan, which are the three running dogs of the United States in Asia," he said.
"We only need to kill one, and it will immediately bring the others to heel."
The military hawks appear to make up only a small proportion of China's officer corps. But their influence, magnified by modern communications and social media, may be far more extensive than their numbers suggest.
Their influence may also be shaping views and actions in the Chinese chain of military command.
Just last month, another hawk, Senior Colonel Liu Mingfu, an analyst at China's National Defence University, said that the US was building "a mini-Nato" to contain China, with the US and Japan at its core, and Australia, another US ally, within its orbit.
He told a correspondent for Australia's Fairfax newspaper group that his views did not represent China's policy but were consistent with what political and military leaders thought, if not what they said.
Col Liu and other hawks have been buoyed by Mr Xi's ascension as China's party and military chief.
One of the Chinese leader's new political mottoes, the "China Dream", echoes the title of a best-selling book by the colonel, which has had sales restrictions removed since Mr Xi emerged at the top.
The US and China's Asia-Pacific neighbours will be hoping Mr Xi sees that it is in China's interest to rein in the hawks, not pander to their extreme views and allow them to dictate policy.
The writer is a visiting senior research fellow at the Institute of Southeast Asian Studies.