The joint naval military exercise China and Russia are conducting in the South China Sea from next week will be a setback for improving already strained China-Asean ties, say analysts.
The military games - the fifth since 2012 - will be held from Sunday to Sept 19 "on the coast and in the water area" of the South China Sea, Russian news agency Tass reported last week.
This is the first time that both navies are conducting an exercise in the disputed waters. An Arbitral Tribunal at The Hague had in July ruled against China's maritime claims in the South China Sea.
China's Defence Ministry confirmed in July that the joint drill will take place in the South China Sea, without giving details on its scale and the exact location.
The joint naval drill shows the mutual support between China and Russia on strategic matters, analysts told The Straits Times.
It is mainly aimed at countering the influence of the United States and its security ally Japan in the region, they added.
"Still, this is not good news for China-Asean relations," said Jinan University analyst Zhang Mingliang.
"Asean countries are already wary of China's military exercises in the South China Sea, and now you have another big power entering the fray," said Professor Zhang.
"This joint show of force will not be welcomed by these small countries," he added.
Beijing-based military expert Song Zhongping pointed out that both navies have conducted drills in the Yellow Sea, the Sea of Japan, the East China Sea and the Mediterranean Sea in the past. It will be useful to hold joint exercises in a completely new site to deepen military cooperation and capabilities against potential threats, he added.
"The South China Sea spans a much wider area and the drill this time will be much larger in scale," said Mr Song.
Given the tensions in the region, Mr Song noted the political considerations behind the cooperation. It shows Moscow's willingness to support Beijing in exchange for economic, political and geopolitical backing in other parts of the world amid Western sanctions, he said.
More importantly, it serves to rebalance a region thrown "off balance" by the US and Japan, he added.
To Prof Zhang, the drill's political value far exceeds its military value.
"I see this as an act of political expediency," he said, adding that given Russia's close military ties with Vietnam, he does not see how Russia will cooperate with China on this front.
Russia expert Yang Cheng of East China Normal University observed that this upcoming drill is a continuation of close military cooperation between China and Russia established in recent years.
While bilateral ties have grown warmer as a result of Western sanctions imposed on Russia over its actions in Ukraine, it is not realistic to expect Sino-Russia relations to move to a higher level as a result of this, he said.
"That said, for as long as there is continued pressures from the West, it's probably a given that both countries will continue to stay close," said Prof Yang.