THE Supreme Court’s En Banc notice dated November 11, 2025, in the habeas corpus petitions filed by Mayor Sebastian Duterte, Veronica Duterte, and Rep. Paolo Duterte on behalf of former President Rodrigo Roa Duterte, did more than set deadlines.
It sketched the legal battlefield: questions on mootness, judicial restraint, Interpol notices, constitutionality of arrest, the Rome Statute, and even the country’s own law on international crimes. The Court then directed all parties to file memoranda addressing these issues.
One issue stands out because it affects not just the Philippines but the international legal system itself. The Court asked whether Article 127(2) of the Rome Statute creates a continuing obligation for the Philippines to cooperate with the International Criminal Court for investigations that began before the country withdrew.
At first glance, Article 127(2) seems like an anti-escape clause. A country that withdraws does not automatically erase obligations it had while still a member.
More importantly, withdrawal “shall not affect” cooperation with the Court for investigations or proceedings “commenced prior” to the withdrawal’s effective date. It also states that withdrawal shall not prejudice the “continued consideration” of matters already before the Court.
This principle was clearly applied in Burundi. By the time Burundi’s withdrawal took effect, the ICC had already authorized a formal investigation. Since that crucial step occurred before the exit date, Burundi remained duty bound to cooperate. International law scholars widely agree this was the correct reading of Article 127(2).
International law experts consistently note that ICC jurisdiction only begins when a formal investigation is authorized. For the Philippines, that happened more than two years after withdrawal. In simple terms, Article 127(2) cannot revive obligations that never existed.
In stark contrast, when the Philippines’ withdrawal became effective on March 17, 2019, there was no ICC investigation yet. The Prosecutor sought permission to investigate only in May 2021, and the ICC granted that authority in September 2021. By that time, the Philippines was no longer a member and therefore no longer bound by treaty-based obligations.
International law follows a basic and practical rule: treaties bind only their members. After withdrawal, a State is freed from future obligations except those already incurred before leaving.
This is reflected in the Vienna Convention on the Law of Treaties, the world’s guidebook on how treaties operate. Since no ICC investigation had begun before March 2019, there was no cooperation duty that could have survived the withdrawal.
But the ICC took a broader approach in its October 23, 2025 decision. It treated the earlier preliminary examination as enough to say the case was “already under consideration” before the Philippines left. The problem is that a preliminary examination is not an investigation. It does not trigger ICC jurisdiction. Treating it as such stretches the Rome Statute beyond its text and even beyond its drafting history.
If this reading were accepted, no country could ever truly leave the ICC. Even the earliest and most routine steps could permanently bind a State long after withdrawal, an outcome inconsistent with how treaties work.
International law experts consistently note that ICC jurisdiction only begins when a formal investigation is authorized. For the Philippines, that happened more than two years after withdrawal. In simple terms, Article 127(2) cannot revive obligations that never existed.
As the country awaits the parties’ submissions, the Supreme Court now stands as the institution best positioned to clarify this debate.
Whatever the ruling, the Court’s guidance will shape not only domestic legal policy but also how the Philippines defines its place in the international legal order.