Moving forward, however, the challenge for the two new-found partners is to translate their high hopes for a sustained 21st century partnership into a geopolitical reality through concrete agreements and institutionalised cooperation.

Just before his visit to Manila, the Chinese leader penned an op-ed, published by Xinhua, which underscored the rapid turnabout in Philippine-China relations. “Our relations have now seen a rainbow after the rain,” the piece proclaimed.

After all, throughout the opening years of this decade, the Philippines and China have had one of the most toxic relationships in Asia.

As a result, there was hardly any institutionalised communication between Manila and Beijing in previous years, particularly under former Philippine president Benigno Aquino, who pursued a more confrontational approach to maritime disputes in the South China Sea.

China and Philippines sign oil and gas exploration deal as Xi meets Duterte

Viewing China as an aggressor, the former Philippine government chose to solidify its defence relations with traditional allies such as the United States, as well as Japan and Australia.

It granted Washington an expanded strategic footprint in the Philippines through new defence agreements, while taking the unprecedented step of suing China at an arbitral tribunal at The Hague over the South China Sea disputes.

The result was a period of intense mutual acrimony, with Xi and Aquino never managing to hold a formal bilateral summit throughout the years. Today, however, the quality and direction of relations between the two countries has changed, unrecognisably.

In a quantum leap from the recent past, China and the Philippines agreed to upgrade their bilateral ties into a strategic partnership during Xi’s visit.

“Just now, the president and I had a friendly, in-depth and a productive meeting,” Xi said during a joint press conference with Duterte.

Five things to look out for on Xi Jinping’s visit to the Philippines

“We charted the future course of China-Philippines relations, and drew an ambitious blueprint for its development.

“[We] agreed to elevate our relationship into one of comprehensive, strategic cooperation,” he said.

Xi also made it clear that the ongoing rapprochement was for real, as it was based on a shared “vision” and “a clear course for China-Philippines relations”.

With the Philippines emerging as a crucial swing state in regional geopolitics, Xi expressed his joy over how improved bilateral relations would send “a strong message to the world that our two countries are partners in seeking common development”.

Calling the two neighbours “natural partners with a common destiny”, he made it clear that China “will continue to do its modest best to help and support the Philippines”.

Philippines prepares red carpet for Xi, but not everyone is happy

Much to his host’s delight, Xi emphasised Chinese help in areas that are close to Duterte’s heart, namely “lending a hand to your counter-narcotics and counterterrorism struggle, to helping to repair roads and bridges in Marawi and build new infrastructure there” after a months-long siege by terrorist elements last year.

For his part, Duterte welcomed the “positive momentum” in Sino-Philippines relations as well as the “deepening trust and confidence [between] our governments”. He described Xi’s visit as a “landmark moment” which had “turned a new page” and started a “new chapter of openness and cooperation” for the two neighbouring nations.

Beyond the rhetorical flourishes, however, the two sides fell short of striking a diplomatic breakthrough on two crucial areas of concern.

Though Xi underscored how the Philippines and China “have a lot of common interests in the South China Sea”, a joint exploration agreement, expected earlier, failed to materialise.

For the past year, Duterte has put forward the notion of “co-ownership” of the disputed resources in the South China Sea as a way forward. China, in turn, has proposed joint development agreements as a mechanism to break the impasse in the area.

The two sides, however, only signed a generic memorandum of understanding on oil and gas cooperation, which, according to Philippine Energy Secretary Alfonso Cusi, was “just a cooperation to explore solutions” on “how we can enjoy the resources” in the South China Sea.

Is Xi’s Manila trip the start of a golden age for China, Philippines?

The pact’s limitations were likely due to rising domestic opposition in Manila to any such deal, leaving the parties still exploring a potential joint exploration agreement. In a joint Senate resolution, two outspoken opposition legislators urged the government against signing any deal that “diminishes the Philippines’ exclusive rights” in the South China Sea. There were also anti-China protests in Manila, reflecting liminal antipathy in the country towards improved ties.

Moreover, among the close to 30 deals signed during Xi’s visit, in only two projects was there an indication of progress in China-assisted infrastructure enterprises: namely, the Panay-Guimaras-Negros Island Bridges Project and the Davao City Expressway.

Other deals were mostly memorandums of understanding, letters and framework agreements, many on already identified projects. As a result, opponents of the rapprochement were quick to criticise Duterte for failing to secure large-scale investment from China.

Beyond a shift in the atmospherics of bilateral exchanges, the momentum of Philippines-China relations will largely depend on the actualisation of big-ticket Chinese infrastructure projects in the Philippines as well as the finalisation of a mutually satisfactory compromise in the South China Sea.

Otherwise, in the foreseeable future, this “golden age” of Philippines-China ties may simply peter out.

Richard Heydarian is a Manila-based academic and author