Japan, a Key Partner for Indonesia's Vulnerable Seas
Budget has become the key word in ensuring the smooth running of government programmes across various sectors, and maritime security is no exception. In January 2026, the Head of Indonesia’s Maritime Security Agency (Bakamla), Vice Admiral TNI Dr. Irvansyah, stated that Bakamla had calculated the need for 274 vessels to secure Indonesian waters until 2045. Currently, the agency possesses only ten ships.
Irvansyah drew a comparison with the Philippine Coast Guard, another archipelagic maritime force facing sustained pressure from China. That agency has around 300 patrol vessels and approximately 30,500 personnel at its disposal. Bakamla’s budget tells a similar story. Irvansyah has appealed to the Ministry of Finance for intervention, noting that the agency’s budget is small but its tasks are large.
When Bakamla requested IDR 7 trillion to finance its operations and maintenance for 2026, it received only IDR 1.4 trillion. According to Irvansyah, this amount is only sufficient to cover everything except maritime patrols. The impact of this shortfall is clearly visible in Indonesia’s Natuna Sea. In June, the local government reported that Natuna fishermen were forced to abandon their fishing grounds after foreign trawlers entered the area. But this is only the smaller problem. Between May and September last year, observers detected Chinese oceanographic research vessels operating at three different points in the North Natuna Sea, coinciding with patrols by the China Coast Guard. A security gap of this magnitude cannot be addressed solely with vessels built in Indonesian shipyards.
The Indonesian government, aware of this, has spent the last four months signing various security cooperation agreements with partners in the Indo-Pacific region. However, Indonesia’s challenges are fundamentally maritime, and no partner offers more solutions than Japan. Earlier this year, Irvansyah confirmed that a new 85-metre patrol vessel is being built for Bakamla in Japan. The vessel features a new design, developed from scratch based on a Japanese survey of Indonesia’s existing fleet. The crew will be trained in Japan and will sail the vessel home alongside their Japanese counterparts. The ship is reportedly scheduled to arrive in 2027.
Beyond the cooperation with Bakamla, a broader and steadily deepening defence partnership between Indonesia and Japan is growing. The two countries signed a Defence Cooperation Arrangement in May, and in June, Defence Minister Sjafrie Sjamsoeddin was in Tokyo to discuss the potential transfer of Asagiri-class destroyers, used submarines, and Mogami-class frigates from the Japan Maritime Self-Defense Force. None of these transfers would have been possible a year ago. For most of the post-World War II period, Japan restricted the export of advanced military equipment. That changed in April when Japanese Defence Minister Shinjirō Koizumi dismantled these restrictions, paving the way for defence exports to countries with which Japan has transfer agreements. Indonesia is one such country.
What has not changed is the expertise underpinning naval cooperation with Japan. The Japan Maritime Self-Defense Force and the Japan Coast Guard have spent decades dealing with the same problems Indonesia now faces: sustained surveillance and response along a long coastline. Both agencies have endured the last five years under unprecedented pressure from China, with China Coast Guard vessels operating around Japan’s Senkaku Islands at record levels. During this period, Japan has built significant expertise and capability in maritime security and amphibious operations. This forms a crucial foundation of Japan’s soft power in the defence technology sector. Japanese patrol vessels and frigates come with established training pathways. Cooperation with Tokyo is the closest offer to what the Head of Bakamla has requested.
The deepening of Indonesia-Japan cooperation can work in two directions. Indonesia’s geography is key to Japan’s efforts to realise a Free and Open Indo-Pacific (FOIP), protected from hostile interference and governed by rules rather than force. The Malacca and Lombok Straits are as vital to Japanese trade as they are to Indonesia’s, and protecting these chokepoints is an essential economic and security interest for the Japanese government in Tokyo. Cooperation with Bakamla, which strengthens the agency’s ability to protect these sea lanes while safeguarding Indonesia’s own sovereignty, emerges directly from this thinking. Aligning with FOIP does not require an alliance. This approach enables cooperation between maritime powers and capacity building without political baggage, precisely at a time when Indonesia needs it.
The question, therefore, is not whether Indonesia has willing partners. The question is whether Jakarta is prioritising the right things. Indonesia’s defence modernisation budget for 2026 reaches IDR 337 trillion. Yet the bulk of these funds is allocated to fighter jets. Meanwhile, Bakamla requested IDR 5.6 trillion to build a national maritime surveillance system consisting of 35 stations across the archipelago equipped with radar, cameras, and drones. That request was rejected. Bakamla has been pleading for support all along.