CHINA - On Monday, China welcomed visiting United States Defence Secretary Chuck Hagel with a tour of its sole aircraft carrier Liaoning, but the feel-good vibes dissipated a day later.
Dispensing with diplomatic protocol, top Chinese military officials crossed swords publicly with Mr Hagel over Beijing's actions in regional territorial disputes on China's maritime fronts, as well as Washington's response.
In separate meetings, Central Military Commission (CMC) vice-chair Fan Changlong and Defence Minister Chang Wanquan told Mr Hagel in full view of the press that China wasn't happy with the US for siding with its neighbours in the disputes and also for selling arms to Taiwan.
Responding with candour too, Mr Hagel reportedly said that the US would protect Japan, its security treaty ally, in the event of a conflict with China, as he accused Beijing of provocation with its launch of an air defence identification zone (ADIZ) last November in the East China Sea.
It was a rare open display of dissatisfaction compared to the usual style of keeping angry exchanges over sensitive topics behind closed doors, say analysts, as they cite several possible reasons.
Beijing-based military commentator Wu Ge cited rising anxiety on both sides that their core interests are coming under threat from each other.
"It is not surprising the talks have turned into public spats as these are issues that both sides cannot achieve common ground on," he told The Straits Times.
For China, core interests include its territorial sovereignty at stake in the maritime disputes; and Taiwan, after the US House of Representatives this week approved US arms sale to Taipei and reaffirmed the Taiwan Relations Act that obligates the US to protect Taiwan in an attack.
For the US, its freedom of navigation in the region is under rising threat from China, with the ADIZ in the East China Sea and a fishing ban against foreign vessels in the South China Sea.
Also, observers say China wants to state publicly its bottom line over the regional disputes ahead of US President Barack Obama's Asian tour later this month, fearing that recent remarks by senior American officials signal more support to come from the US for its allies.
Mr Obama will visit South Korea, Malaysia, Japan and the Philippines. The latter two are US allies fiercely opposed to China's territorial claims. "Obama needs to pay serious consideration to this issue when he comes to Asia... China has already put this message across during the meetings with Hagel," said former Chinese diplomat Ruan Zongze. "The US is moving in a direction we don't want to see, taking sides with Japan and the Philippines, and China is extremely unhappy about this."