evidence: Few people will have heard of it and it has barely hit the global headlines, compared to key waterways such as the Malacca Strait, but the Sulu-Celebes Sea, encompassing the waters around Indonesia, Malaysia's eastern Sabah state and the Philippines, has become an area of growing concern. [...] Successive joint statements continued to agree to explore measures such as co-ordinated patrols and a safe vessel transit corridor through the Sulu-Celebes Sea. [...] However, successfully carrying out this trilateral maritime security framework will require all three governments to sustain their commitments, including the need to put aside political concerns - such as the question of sovereignty between Kuala Lumpur and Manila over Sabah, since Mr Duterte has insisted that his administration "will stick to our claim".