0859 GMT May 22, 2018
The decades-old tradition appeared headed for the history books last year as a newly-elected Duterte pivoted toward China – and away from long-time ally the US, AFP reported.
But the number of troops taking part in the drills has increased by a third from last year to 8,000, a return to figures seen in years past when the exercises served as a thinly-veiled deterrent to China.
The reason for Duterte's change of heart on the two-week drills codenamed "Balikatan", or "Shoulder-to-Shoulder", may be down to what experts see as careful efforts by the Filipino military to restrain their unpredictable president.
"The fact it's being done under this administration means they (Duterte's government) now have a better understanding of the security equation," political analyst Victor Andres Manhit told AFP.
Though the bulked-up maneuvers – including a live-fire component that was dropped last year – took place on a naval base just 180 kilometers (110 miles) east of the Filipino-claimed Scarborough Shoal that China has controlled since 2012, the drill's leaders barely mentioned Beijing.
China claims most of the South China Sea, a strategic waterway believed to harbor significant oil and natural gas deposits, but their assertion was ruled illegal in 2016 after Duterte's predecessor Benigno Aquino filed suit before an international maritime tribunal.
Duterte has since reversed course and set the ruling aside, along with long-simmering friction over competing claims to the waters, in order to court Chinese trade and investment.
He has also cut two major annual naval exercises with the US and last year reduced the Balikatan contingent to 5,400 American and Filipino troops.
The decision came at a low point for US-Philippine relations, when Duterte hurled insults at the American ambassador to Manila and served notice that the 2017 edition would "be the last military exercise" with the United States.