"In 1963, the resource-rich [OIL] territory of Sabah, which had been under British control since the late nineteenth-century, formally became part of the Federation of Malaysia. The Philippines, however, protested this, claiming that Sabah had never been sold to foreign interests, and that it had only been leased (padjak) by the Sulu Sultanate and therefore remained the property of the Sultan and by extension the property of Republic of the Philippines."
Yet more instance from modern history that I was vaguely familiar with, BUT WITHIN THE CONTEXT OF THE ROYAL SULU ARMY AND THE RECENT INVASION OF SABAH, MOST INTERESTING.
The Jabidah massacre. That "catalyst" leading to the current Islamic insurrection in the southern Philippines. A guerrilla campaign that has been waged for over FORTY YEARS NOW and only recently has resolution of a sort been reached.
"The Jabidah massacre, also known as the Corregidor massacre, refers to an incident in which members of the Armed Forces of the Philippines (AFP) are said to have massacred a number of Moro Muslim recruits who were escaping their covert training to reclaim Sabah. Sources differ regarding the details, with the number of victims ranging from 14 to 68, and some sources asserting that the massacre is a myth. The massacre happened on March 18, 1968. The Jabidah Massacre is widely regarded as having been the catalyst behind the modern Moro insurgencies in the Southern Philippines."
Filipino soldiers, Moro [Filipino Muslim] each and everyone of them, shot dead by their own army. A response to mutiny. The Moro contingent as organized, trained and instructed to wage guerrilla warfare in Sabah. Discontentment among the Moro troops leading to rebellion and eventual mass execution.
The consequences and response four decades of conflict those Islamic factions of BIFF, MILF, MNLF, and Abu Sayyaf having an amazing resiliency and endurance.
That government in Malaysia, ever watchful as I might well assume, they too have not forgotten the Jabidah massacre? The Royal Sulu Army is yet just one further manifestation of events that originally transpired decades ago? Could be.