President Barack Obama has only a handful of months left in office, but facing the shock loss of a pivotal Asian ally in the Philippines, his White House is playing a long game.

Filipino President Rodrigo Duterte says a lot of things. Most notably, the capricious 71-year-old has called Obama (and Pope Francis) a "son of a whore."

This week he declared decades of US-Filipino ties over, although he later qualified that remark.

"We haven't heard any specifics" said White House spokesman Josh Earnest, "but those comments are creating unnecessary uncertainty in our relationship."

On the face of it, Duterte's casual desecration of a 65-year-old military alliance and his eager embrace of China are blows for US influence and for Obama's "pivot to Asia."

The United States risks losing presence and access to ports and bases in the heart of the South China Sea -- a contested geopolitical hotspot.

Under Duterte's predecessor Benigno Aquino, China and the Philippines were at loggerheads over the contested economically vital waterway -- to the point that senior US officials worried about being dragged into a war with China.

But since Duterte took office in June, he has suspended joint US-Philippine patrols and threatened an end to joint military exercises.

A split would have regional ramifications. Duterte's sinophile turn could further split the ASEAN regional bloc, which Washington has cultivated as a counter to Beijing's designs on dominance.

China's hardline territorial claims and confrontational stance had given Washington the upper hand.

"The region was in many ways coming to the realization that China is not a reliable long term partner," said Lyle Morris of the Rand Corporation.

But Beijing is picking off cash-strapped ASEAN members like Cambodia and drawing them into its orbit with vast infrastructure spending.

Duterte's recent visit to Beijing -- the provocative setting for comments on dissolving US relations, bagged him billions of dollars in deals.

"A key motivator driving the Philippine president to mend fences with China is economic," said Murray Hiebert of CSIS.

The souring with Washington could also hit counterterrorism operations against the Abu Sayyaf Group, which has been linked to Al-Qaeda and has carried out bombings, murder and kidnapping.

- Echoes of Estrada? -

In its response, the White House has been wary of one lesson of Duterte's whole political career -- from mayor of Davao to president of the republic -- he has a short temper.

Officials have limited public chastisements, particularly over Duterte's war on crime, which has claimed about 3,700 lives in less than four months and raised fears about mass extrajudicial killings.

"He's very very sensitive to criticism," said Rand's Morris "So any time we do -- like with the extrajudicial killings -- he gets really really upset and that forces him to make decisions that might not be in the best interest of the Philippines."

Instead, the White House has largely been content to weather the storm as best it can and stress the relationship is bigger than Duterte.

As officials tweet about events around "Filipino American History Month" they point out that day-to-day contacts have little changed since Duterte came to office.

For all Duterte's bluster, he has not followed through.

Even some Philippine officials admit they are as befuddled by Duterte's intentions as their counterparts in Washington.

Many believe that his ability to carry out his "separation" may be limited by his own politics and popular opinion.

He would have to secure legislative support to withdraw from the mutual defense treaty, which underpins the relationship.

There is little sign that support is there. Despite being former US colonial subjects, Filipinos are overwhelmingly pro-American.

Within the armed forces -- particularly the Navy and Airforce -- there is already deep unease about his pivot to China.

In some quarters Duterte is being compared to Joseph Estrada -- the populist former president who was ousted in 2001 amid mass protests.

- Jobs, jobs, jobs -

The Obama administration has begun to gently push back against the most egregious insults and actions.

It cancelled a planned meeting with Duterte in Laos and has warned ominously about "uncertainty" in corporate board rooms.

Aside from the war on drugs and America's perfidy, Duterte's favored topic of conversation is the economy.

Here, the United States has some leverage.

It is the second largest foreign direct investor to the Philippines -- after the British Virgin Islands, an off-shore tax haven -- according to Santander bank.

US-Philippines Trade ties date all the way back to 1797, when "the Astrea" was the first US vessel to return from the Philippines, loaded with indigo, hemp, spices and sugar.

Ultimately, that history and America's trading clout may provide Obama -- and his successor -- with a port in this storm.