Sabah is the 2nd largest state in the Malaysian Federation. In addition, Sabah is home to a huge plantations as well as oil refineries and natural gas deposits. The Malaysian Armed Forces will not relinquish control of Malaysia without a fight.
Realistically speaking, Sabah cannot be reclaimed unless Malaysia relinquishes military control, or if the Philippines takes it by force. At the current situation, both parties are trying to solve this issue and maintain the status quo.
The Malaysian Armed Forces, however, are having a difficult time "wiping out" the Sulu Royal Army. Decades of peace in Malaysia have resulted in their army's inability to counter the guerilla warefare tactics of the Sulu Royal Army. It is also known that the MNLF have now sent hundreds of its battle-hardened forces to Sabah to reinforce the Sulu Royal Army.
I find it quite ironic how this situation has come to be. The MNLF as well as the Sulu Royal Army were trained by the Malaysian Armed Forces to combat the Philippine Government years prior. Now, the MNLF is now at war with the Malaysian Armed Forces.
Now Malaysia can taste and see the results of guerilla warefare. Malaysia as a nation has provided resources and support for muslim insurgents in Southern Thailand, in Indonesia and even in the Philippines. Malaysia is now tasting a little bit of karma.
They are now fighting people who they trained and encouraged to fight the Philippine Government.
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