Vietnam and the Philippines agreed at the end of August to boost their defense links and deepen collaboration on maritime security.

The announcement came as Vietnam's Defense Minister Phan Van Giang visited Manila for talks with his Philippine counterpart, Gilberto Teodoro.

Both ministers inked "letters of intent" to enhance their maritime and disaster response engagements. They also agreed to resolve disagreements peacefully and within the framework of international law.

An official security agreement is expected to be signed by the end of the year.

The announcement comes amid high tensions between the Philippines and China over their territorial dispute in the South China Sea (SCS).

A symbolic move?

But experts say Hanoi's decision to forge closer ties with Manila is, at this stage, mostly for show.

"I think the move is largely symbolic for now. I don't expect a significant breakthrough in defense cooperation between Vietnam and the Philippines, given their differing approaches to the South China Sea dispute," Nguyen Khac Giang, a visiting fellow at the Vietnam Studies Program at the ISEAS – Yusof Ishak Institute in Singapore, told DW.

"However, in the long term, this could be important if ASEAN claimants seek to form a more united front in addressing China's maritime aggression," he said, referring to the Association of Southeast Asian Nations, a 10-nation regional bloc. 

"Without such coordination, it will be extremely difficult for individual claimant states to negotiate with China bilaterally."

Zachary Abuza, a professor at the National War College in Washington focusing on Southeast Asia politics, said the announcement is a good diplomatic move by both Vietnam and the Philippines.

"Phan Van Giang's visit to Manila was important diplomatically, much less so militarily," he noted.

"The Philippines has such paltry maritime capabilities. Vietnam has more naval capabilities but is very cautious to use them. There is insignificant training and deployments are rare. I still think this is good because more bilateral military engagements are a way to force the Vietnamese to deploy, exercise, and engage more."

What's the South China Sea dispute about?

Beijing lays claim to almost the entire South China Sea, through which $3 trillion (€2.7 trillion) worth of trade passes annually. The waterway is also believed to be rich in oil and natural gas deposits, as well as fish stocks.

Vietnam, Brunei, Malaysia, the Philippines and Taiwan all dispute Beijing's territorial claims.

The Permanent Court of Arbitration in 2016 found China's sweeping claims had no legal basis. Beijing rejected the ruling.

China and the Philippines have been engaged an escalating confrontation over disputed shoals in the SCSthis year. 

Manila and Beijing have exchanged accusations of intentionally ramming Coast Guard vessels in the disputed waterway in recent months, including a violent clash in June in which a Filipino sailor lost a finger.

The incidents have overshadowed efforts by both nations to rebuild trust and better manage confrontations, including setting up new lines of communication to improve their handling of maritime disputes.

Dividing ASEAN over SCS

Amid high tensions, the US has vowed that it will defend the Philippines from any attack in the SCS.

Washington and Manila have had a mutual defense treaty in place since 1951.

But for the Philippines, having an agreement with Hanoi is also significant, said Abuza, pointing to Beijing's efforts to weaken ASEAN by dividing the bloc.

"I think that China has so effectively divided ASEAN that the only way to move forward is minilateralism,"  he said, referencing an increasingly popular model of small groups of nations cooperating based on shared interests.

"China takes such advantage of the fact that the Southeast Asian claimants themselves cannot come up with a common position," Abuza noted. "China's preferred stance is to deal with each claimant individually; they do not want this to be a multilateral issue."

Vietnam's different approach

Vietnam, for its part, also has a decades-long dispute with China over the South China Sea.But exchanges between the two sides over the issue have been low-key since 2011, when Hanoi and Beijing agreed to manage their differences diplomatically to prevent further escalation of the dispute. 

"Vietnam is currently in a better position than the Philippines, but this could change quickly," said Nguyen Khac Giang, the ISEAS – Yusof Ishak Institute researcher.

"Tensions can flare up, as seen during the oil rig crisis in 2014 or the Repsol incident in 2017. Hanoi is well aware of this and has been working to strengthen partnerships with countries both inside and outside of ASEAN on the South China Sea issue, all while maintaining a good relationship with Beijing."

To bolster its presence in the SCS, Vietnam has also ramped up its building of islands in the disputed waterway by dredging and filling in land, as well as fortifying barriers.

Beijing has long been building artificial islands in the SCS and turning them into military installations.

Nevertheless, China has not interfered with Vietnamese activities in the region in the same way it has with the Philippines.

"Obviously, the Chinese are unhappy about it, but they've done nothing so far to interfere or stop it. The Chinese usually focus on one country at a time, because they don't want to force a multilateral response," said Abuza.

Edited by: Srinivas Mazumdaru