SINGAPORE — At the beginning of last week's International Maritime Defence Exhibition (IMDEX) here, China and the US appeared to have moved forward on crisis management measures that would help stabilize the region. , but b By the end of IMDEX, the situation appeared worse for wear.

On the first day of the exhibition, IMDEX, US Navy Adm. Michelle Howard, vice chief of naval operations, told a media roundtable that the Code for Unplanned Encounters at Sea (CUES) agreed upon in 2014 between China and the US had been was successfully implemented and tested in real time just before IMDEX began when CUES was used between the USS Fort Worth (LSC-3) littoral combat ship and a Chinese warship in the South China Sea.

Both the Fort Worth and a Chinese Type 54A Jiangkai II frigate, 569 Yulin, were on display at Changi Naval Base for IMDEX as part of a 20-warship exhibition.

"We had previously agreed with the Chinese, if we met at sea, to use CUES. So Fort Worth came across one of our counterparts" and the encounters were handled in a professional manner, Howard said.

Navy chiefs at the Western Pacific Naval Symposium in China approved the use of CUES on a voluntary basis in April 2014, said Carl Thayer, a Southeast Asia security specialist at the Australian Defence Force Academy.

"CUES is an important first step at norm setting and institutionalizing agreed procedures when military ships unexpectedly encounter each other at sea," Thayer said. "So far there have been at least three bilateral naval exercises practicing CUES: China-Indonesia, Vietnam and the US, and Japan and the Philippines."

Sam Bateman, research fellow at the Australian National Centre for Ocean Resources and Security, University of Wollongong, said CUES was an important step forward for improving understanding and confidence between regional navies although it only applies to naval ships and aircraft and not to coast guard vessels.

Many of the recent incidents involving China and its regional neighbors have involved the Chinese coast guard, provincial maritime patrol vessels and fishing boats, so "CUES has been supplemented at a bilateral level between China and the US by a memorandum of understanding concerning rules of behavior (ROB) for safety of air and maritime encounters," he said.

On day two of IMDEX, the commander of China's South Sea Fleet spoke at the International Maritime Security Conference about joint efforts among China, its regional neighbors and the US to build a "safe and harmonious ocean."

Rear Adm. Shen Jinlong cited Chinese President Xi Jinping's declaration at last year's fourth Conference on Interaction and Confidence Building Measures in Asia (CICA) in Shanghai that China would help build a new security framework in cooperation with its neighbors. to ensure peace.

"We have normalized the maritime consultation mechanism with the US Navy built on communication and coordination mechanisms with many countries' counterparts, and regularly exchanged maritime information," Shen said.

Later that same day, US Navy Rear Adm. Charles Williams, commander of the Logistics Group Western Pacific, toured the Chinese frigate Yulin. , a Type 54A Jiangkai II-classfrigate. The reception by the Chinese crew was exceptionally friendly.

By the third day of IMDEX, media reports from out of the region indicated China had issued a radio warning to US military surveillance aircraft nearing Chinese-controlled islets in the South China Sea. The incident was a result of a freedom of navigation (FON) exercise announced by the Pentagon earlier this month, which will involve the US military sailing and flying within 12 nautical miles of islands under a Chinese land reclamation program and claimed as sovereign territory.

"I think it's now time for China to talk about what the reclamation of land means," Adm. Howard said. "I mean, when I look at it, it's a couple thousand acres ... and no one's saying they are putting a resort out there, so someone needs to explain what they are putting out there."

"Danger areas that remain are, first, none of these documents cover submarines, and secondly, they don't cover air operations," Bateman said. Despite the rules of behavior ROB referring to air encounters in its title, "I understand the planned appendix to the main document dealing with air encounters has not been agreed yet."

A dangerous air encounter may be the most likely scenario, possibly has the highest likelihood, Bateman said. "The air space around the disputed islands can be very busy with so many different air forces possibly operating in the area."

For example, around the Japanese administered Senkaku Islands, claimed by China as the Diaoyu Islands, "there could be aircraft from air forces and navies of five or more countries," not to mention the overlapping air defense identification zones of Japan and China.

A more general limitation is that CUES and rules of behavior ROB are all really at a tactical level, Bateman said. There is there is still a regional need for an agreement aimed more at the operational and strategic level. Such an agreement might cover issues such as safety zones around disputed features, restrictions on particular types of operation in particular areas, such as submarine "no go" areas, hot lines, operational transparency, and prior notice of operations.

"Unfortunately such a document is unlikely in the current strategic environment but it should be an objective to 'demilitarize' both the South and East China seas," Bateman said.

China's charm offensive at IMDEX and its muscular behavior in the East China Sea and South China Sea might be part of a larger strategy beyond the tactical, said Paul Giarra, president, Washington-based Global Strategies & Transformation.

"China's unpredictability and supposed irrationality are one naval diplomat's scourge, and another's strength," he said. "China's willingness to participate in and adhere to these regimes will determine their relevance."

He said this is not because they are designed to capture China in a "Western-logic, rules-based set of agreements," but a process of practical involvement designed to reduce the likelihood of flashpoint incidents and "more importantly to induce Chinese involvement in rationalizing procedures."

This is intended to build confidence and predictability, but it remains to be seen whether China agrees that these are "positive attributes in the current competitive circumstances."

"Not so long ago, American unpredictability was our strong suit," Giarra said.