On August 5, there was a sign of blossoming international relations even as global hostilities in trade, currency and diplomacy intensified: the EU and Vietnam signed a historic defense agreement -- the first in Southeast Asia.

The agreement paves the way for Vietnam's participation in European military missions, peacekeeping operations and tighter defense cooperation, and comes as Europe extends its strategic ambition to East Asia, just when China is challenging the existing order.

Though European powers are keen on maintaining robust and fruitful relations with Beijing, they have rightly shown their willingness to uphold a rules-based order in the region. In recent years, the U.K. and France have stepped up their naval presence in China's adjacent waters, while the EU and its key members have fortified economic and strategic relations with smaller Southeast Asian states.

There are multiple reasons for European to get involved in East Asia.

First, it is consistent with the EU's principles and strategic doctrine. While it has remained neutral about territorial and maritime spats in the South China Sea, its 2016 Global Strategy calls on member states to "uphold freedom of navigation," respect the Law of the Sea and "encourage the peaceful settlement of maritime disputes."

Moreover, its 2014 Maritime Security Strategy expects EU members' armed forces to "play a strategic role at sea and from the sea," undertaking "the full spectrum of maritime responsibilities." This includes, crucially, supporting freedom of navigation in international waters and deterring "illicit activities."

Given its additional commitment to maintaining maritime security in the South China Sea, it certainly seems that China's relentless militarization of the disputes poses a direct threat to these basic values.

The EU's defense deal with Vietnam thus underscores its commitment to aid smaller nations to protect their sovereign rights and legitimate interests, as well as to "safeguarding the rules-based multilateral order," as an EU official said.

Its timing is important. Over the past month, Vietnam and China have been at loggerheads over the Vanguard Bank, a contested energy-rich area in the South China Sea that falls within Hanoi's continental shelf.

In the past decade, Vietnam has bolstered its diplomatic and military efforts to stem further Chinese intrusion into its waters and harassment of its fishing and energy exploration activities in the South China Sea.

The EU has already signed similar defense deals with key U.S. allies such as Australia, which have also raised concerns over Chinese assertiveness in their neighborhood.

The defense deal should be the start of expanded EU action in Southeast Asian. While the U.S. and Japan have assiduously facilitated the development of robust Coast Guard forces among smaller Southeast Asian nations for a decade now, the EU should move in similar direction.

It should also -- alongside the U.K., France and Germany -- continue upgrading strategic relations with China's perturbed neighbors, including the Philippines, Malaysia, Indonesia and Singapore. That means more of these defense agreements should be in the pipeline.

Europe can and should provide assistance, whether through defense grants, joint military exercises and training or the transfer of technology, to improve maritime surveillance and security capacity among these countries.

Individual European nations are already pushing back against Chinese maritime expansionism in Southeast Asian. Still in possession of post-colonial territories across the Indian and Pacific Oceans, both the U.K. and France have regularly deployed naval assets to China's adjacent waters.

Beijing has vehemently opposed these deployments, even disinviting the French from an international naval exercise this year, while threatening negative implications for post-Brexit trade negotiations with the U.K.

Both powers, however, have signaled their deep commitment to uphold freedom of navigation and overflight in China's maritime backyard. In fact, the U.K. has announced its intention to deploy the Queen Elizabeth aircraft carrier to the South China Sea, while working with France on joint maritime exercises and enhancing the ability to operate together in military situations with Japan, India and Australia across the Indo-Pacific.

Through their naval deployments to contested waters and defense agreements with smaller Asian countries, Europe lends legitimacy to Washington's Freedom of Navigation Operations. In effect, Europe and the U.S., along with the naval powers of Japan, India and Australia, are now collectively upholding the freedom of the seas.

The EU also recognizes that defense and trade can go hand in hand as part of a bigger strategic interest. The defense deal with Vietnam came on the heels of the signing of the EU-Vietnam free trade agreement in June, which Brussels has described as "the most ambitious free trade deal between the EU and an emerging economy to date."

In October 2018, the EU signed another FTA with Singapore, underscoring the flourishing of strategic relations between the EU and members of the Association of Southeast Asian Nations. The EU is exploring FTAs with other major ASEAN countries, including the Philippines and Thailand, although both of these have been put on hold because of adverse political developments in each country.

The greater European contribution to peace and stability in the region makes it clear that rising tensions in East Asia are not being left to a cynical Sino-American superpower rivalry.

Instead, we are witnessing multilateral efforts among like-minded powers to protect international public goods and constrain China's maritime ambitions. Europe should become a bigger part of this collective movement to preserve a rules-based order in Asia.

Richard Heydarian is a Manila-based academic, columnist and author of "The Rise of Duterte: A Populist Revolt Against Elite Democracy" and forthcoming "The Indo-Pacific: Trump, China and the New Struggle for Global Mastery."