WE have had two serious Mindanao-centric secessionist movements in our history. Nur Misuari, a contemporary of the late Jose Ma. Sison at the University of the Philippines, wrote down the seminal — and markedly secular — ideological and organizational outlines of the Moro National Liberation (MNLF) while at the university. The second was the MNLF's spinoff, the religiously inclined Moro Islamic Liberation Front (MILF). The leaders of both groups may have not abandoned their secessionist dreams even after so many deaths and so much bloodletting. But for all intents and purposes, the two are both moribund organizations supplanted by extremely violent and scorch-the-earth Islamist forces.

I asked a dozen university students if they know something about the MNLF and MILF. They instead told me to ask them this question: "Why did the Eras Tour skip Manila?" — and they promised to give me comprehensive answers covering both civics and musicology.

The attempt by big landowners to secede Negros Island over land-reform issues during the presidency of Corazon Aquino generated a lot of publicity but failed to gain even the smallest traction. The other was the tragicomic, on-off attempt to make the Cordilleras a separate republic. Lesson: You can't build secessionist aspirations on mere whimsy.

So what do political scientists make of the secession threat of former president Rodrigo Duterte? Is this a serious thing? Even if Mr. Duterte were deadly serious, does he have the wherewithal and enough followers that can transform that threat into a full-blown secessionist movement, complete with political and armed components? Only the second question has an answer: political leaders in Mindanao said "no," and the administration of Ferdinand Marcos Jr. said there would be punitive actions should Mr. Duterte convert his words into action.

But here is the rub. Even if Mr. Duterte was only half-serious when he made the threat and had no intention of converting his words into the Marxist praxis, the substantial reportage by the world's leading newspapers on his secessionist outburst already left on the foreign community an impression that it posed a serious challenge to the government of Mr. Marcos. By "foreign community," we refer to the world leaders who Mr. Marcos wants to impress with his "Bagong Pilipinas." That also includes the foreign investment community, which his administration also wants to impress. The reason: if foreign investors feel positive about what they see in the country, they will have it in their map and under consideration when they make their investment decisions for this year and beyond.

In the standard investment rulebook of foreign investors, their first consideration before placing their money is good governance, a broad term that also means a stable political environment and the rule of law. A secession threat from the previous president whose daughter is the current vice president was a direct assault on the official claim that we have a stable political environment and a turn-off for the foreign investment community.

Mr. Marcos wants the outside world to see what he calls the "structural changes" under Bagong Pilipinas, the foreign investment community included. Mr. Duterte's threat gave a different impression, and a totally negative one: a nation threatened by balkanization and one that presents the optics of a banana republic.

But the threat of Mindanao seceding is just the subtext to a bigger story being closely monitored by most Filipinos and the foreign community. This is the "war of clans," or the breakup of the Marcos-Duterte political coalition. The war of clans has its current manifestations in the form of the verbal skirmishes between the two camps, including the call from one of Mr. Duterte's sons for the resignation of Mr. Marcos. The low point was Mr. Duterte's insinuation that Mr. Marcos was on the Philippine Drug Enforcement Agency watchlist. Mr. Marcos shot back: Was Mr. Duterte on fentanyl?

This reminded the foreign community of the factional wars in Sudan and other parts of impoverished Africa, but without the physical violence.

The nation and the world at large are trying to find answers to this question: Where would all this lead? If you think the foreign investment community that everyone in power wants to invest in the Philippines will just dismiss the war of the clans as "one of those mundane things," you are wrong. The most salient feature of a functional democracy is political stability, not the open and possibly internecine war between the two most powerful political families in the country.

The fractures in our challenged democracy are actually a trifecta. The third is the allegation that bribe money has been underwriting the efforts of the House of Representatives to effect constitutional change through the modality called "people's initiative" (PI). There are critics who claim to have proof that the signature drive for PI is undergirded by bribe money and that public-works contractors who are themselves House members have been bankrolling the signature campaign. What, other than banana republics, bribe people to show manufactured support for a sham constitutional change effort?

The sad spectacle of a Marcos-Duterte open warfare has a subsidiary political fight just as intense: Senators and House members accusing each other of nastiness and plotting dirty, unconstitutional schemes.

The current trifecta of ruptures is not representative of a vibrant democracy that Mr. Marcos seeks. They are the optics of a banana republic.