Maritime terrorism in Southeast Asia refers to acts of extreme maritime violence committed with political motives within the Southeast Asian region. Despite seaborne terrorist attacks accounting for only 2% of all international terrorist incidents from 1978 to 2008, according to RAND's Terrorism Database, Southeast Asia has proven a hotbed of maritime terrorism. Due to the high frequency of pirates in the region, many Southeast Asian-based terrorist groups have appropriated piratical tactics in carrying out their violent political struggles. In 2003, the International Maritime Bureau reported that out of the 445 actual or attempted piratical attacks on merchant vessels, 189 occurred in Southeast Asia, which was more cases than either Africa or Latin America, with 121 attacks occurring in Indonesian waters and 35 attacks occurring in Malaysian and Singaporean waters. In 2004, while the number of actual and attempted attacks fell to 325, Southeast Asia remained at the top of the regional rankings, with 93 incidents occurring in Indonesian waters. Between 2014 and 2018, 242 attacks occurred in Southeast Asia, with the majority occurring in Indonesian waters. The most popular weapons of choice among Southeast Asian maritime terrorists have been explosive devices and firearms, which were used in roughly 60% of maritime attacks in the region.

The concepts of maritime terrorism Definitions of maritime terrorism Maritime terrorism, like terrorism itself, is an essentially contested concept. Because there are over 100 definitions of terrorism from multiple sources, there is no commonly held definition. However, despite this situation there are still multiple UN conventions and regional legal processes to respond to maritime terrorist incidents.

The most prominent definition for maritime terrorism within Southeast Asia seems to have been given by the Council for Security Cooperation in the Asia Pacific (CSCAP) Working Group who defined maritime terrorism as:

However, according to Sheng, beyond the specific definition of maritime terrorism provided by the CSCAP, legal and political analysts are faced with a paradox; given that there is no universal definition of ‘terrorism’, how can a definition of ‘maritime terrorism’ possibly be reached, considering its status as a subvariant of terrorism?

International maritime laws and treaties Before 1988, there had been a debate within the international legal community as to whether acts of maritime terrorism could be meaningfully prosecuted under anti-piracy legislation put forward as a part of the UNCLOS III agreement in 1982. The main debate took place around what precisely was meant by the ‘private ends’ that UNCLOS III classed as an attribute of piracy. International legal scholars like Douglas Guilfoyle argued that ‘private’ referred to a lack of state sanctioning behind the act, viewing ‘private’ and ‘public’ as the relevant dichotomy. Other scholars, like Saiful Karim, argued that ‘private’ referred to the presence of a profit motive behind the act, thus viewing ‘private’ and ‘political’ as the relevant dichotomy. Karim based this assessment off attempts to codify anti-piracy laws that date back to committee work by the League of Nations during the inter-war period.

A foundational convention that has been important in defining maritime terrorism was the Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation (SUA) of 1988 and its accompanying SUA Fixed Platform Protocol. Although SUA 1988 did not define either ‘terrorism’ or ‘maritime terrorism’, it was a response to the 1985 attack on the Achille Lauro cruise ship, a high-profile terrorist incident. The United Nations General Assembly subsequently requested the International Maritime Organisation (IMO) to study terrorist attacks aboard or against ships, with an aim towards making recommendations for countermeasures. In November 1986, Italy, Austria and Egypt submitted a draft to the IMO for a new convention for the suppression of maritime terrorism, which had taken influences from 3 previous counterterrorist conventions; the Hague Convention on Aircraft Hijacking, the Montreal Convention on Sabotage of Airplanes and the International Convention Against the Taking of Hostages. After 2 years of deliberation, the IMO adopted the 1988 SUA Convention. The provisions of the convention made the threatened or actual hijacking, damaging or destruction of vessels and violence against crew prosecutable offences under the convention as such acts threatened the safe navigation of ships. Unlawful acts committed for both private and political ends were covered under the convention and an obligation was imposed on all states party to the agreement to extradite or prosecute convention offenders resident upon their territory. The SUA Fixed Platform Protocol was also signed at the 1988 Rome Convention after the United States and Spain raised the issue of fixed platforms as potential terrorist targets. The SUA Protocol thus made it a prosecutable offence to launch attacks against a fixed platform on the proviso that the fixed platform is attached to the seabed, serves economic purposes like resource exploration or exploitation and operates on a continental shelf.

However, the 1988 SUA Convention and Protocol did possess several flaws, one of which was that both pieces of legislation were reactive towards maritime terrorist acts and offered no preventative provisions or measures to prevent maritime terrorist acts from taking place, as put forth by Justin S. C. Mellor. In effect, the legislation was merely in place to prosecute perpetrators in the aftermath of the crime rather than provide contracting states with powers and legal authority to interdict and prevent violations of the 1988 SUA Convention and Protocol.

Following 9/11, the IMO adopted IMO Assembly Resolution A.924(22) which called for a review of existing legislation and measures that aimed to prevent terrorist acts against the safety and security of passengers, crew members and vessels. In October 2001, the IMO Legal Committee initiated a review of the 1988 SUA Convention and Protocol, with April 2002 witnessing the creation of a US-led Correspondence Group which would provide the IMO Legal Committee with a working paper containing potential amendments to SUA 1988 for the Legal Committee's 85th session in October 2003. The amendments suggested by the Correspondence Group presented before the IMO Legal Committee included 7 new offences under Article III of the 1988 SUA Convention and new provisions authorising the boarding and searching of foreign vessels in international waters who are either suspected of involvement in or are at risk of being targeted by acts prohibited under Article III. Although most IMO delegations expressed support for the amendments, concerns were raised concerning the amendments’ effects on freedom of navigation and the exclusivity of flag state jurisdiction over their vessels within international water. After three years of deliberation, the IMO Legal Committee completed its review during its 90th session during April 2005, with the resulting International Conference on the Revision of the SUA Treaties in October 2005 resulting in the official adoption of the 2005 SUA Protocol. New offences under the protocol included the knowing and intentional weaponisation of ships with terrorist motivation, the knowing and intentional transportation of WMDs and related materials via the high seas both with or without terrorist motivation and the knowing and intentional use of a ship as a transportation means for any person who has committed an offence under any current or future UN terrorism conventions, including the 1988 SUA Convention and the 2005 SUA Protocol.

Piracy-Terrorism Nexus However, the piracy-terrorism nexus creates a theoretical-legal problem in relation to the legalistic conceptualisation of maritime terrorism outlined above. This nexus involves maritime terrorist acts where the tactic, immediate motive and long-term motive of maritime terrorists are mismatched, showing piratical characteristics over exclusively terrorist ones. These acts include the co-optation of pirates by maritime terrorists to do acts like hijacking and delivering a tanker to maritime terrorists for use as an attack delivery system, meaning the pirates would have indirectly assisted maritime terrorist activities. Other acts include maritime terrorists using piracy to extort and generate funds for their political cause. Both these acts are, tactically speaking, piratical, yet, strategically speaking, of a terrorist nature. Some maritime security analysts, like Peter Chalk, argue that this type of co-operation between pirates and maritime terrorists is implausible on a significant level due to their differing incentives and motives. Others, like Graham Gerard Ong, suggest that pirates and maritime terrorists are remarkably similar due to their transnational nature, similar tactics and weaponry and similar levels of accompanying extreme violence. This legal fuzziness and definitional ambiguity surrounding the legal classification of these illegal activities for prosecution has led to the conception that piracy and maritime terrorism exist on a continuum between each other. The Terrorism Financing Convention partially resolves this legal conundrum posed by the piracy-terrorism nexus for, by intentionally partaking in funding activities for illegal acts under numerous international treaties, including the SUA conventions, one can be prosecuted under the Terrorism Financing Convention. As the treaty punishes intentional collaboration with and enabling of maritime terrorist actors and explicitly mentions terrorism in its title, the treaty effectively punishes offenders as complicit with maritime terrorists.

Maritime Terrorist tactics Within academic communities, it has been observed that maritime terrorists use an array of tactics in the perpetration of their attacks. There have also been speculations as to how maritime terrorist tactics might evolve in the future.

Martin N. Murphy identifies multiple means and tactics historically and currently utilised by maritime terrorists, including boat borne IEDs and naval mines. Within Southeast Asia, this has included:

-Suicide bomber divers or ‘human torpedoes’: Multiple attacks of this variant have been attempted within Southeast Asia. Al-Qaeda planned to use suicide bomber divers on US Navy vessels docked in Indonesian ports in 2002. In 2005, an ASG operative by the name Gamal Baharan stated that he had gone to a Palawan island ASG training camp in preparation for an underwater suicide bombing attack that was in the process of being planned by Jemaah Islamiyah. Attacks using a suicide bomber diver or an explosive-laden swimmer delivery vehicle could be used to attack several different types of maritime targets, including warships, naval bases, underwater oil pipelines or underwater telecommunication cables.

-Submarines as vehicles of terrorist transportation: There have been two notable instances of terrorist either obtaining or attempting to obtain these capabilities. The first was in 1999 where the Moro Islamic Liberation Front within the Southern Philippines had enquired as to the possibility of purchasing mini-submarines from North Korea. The second was in 2000, where the Tamil Tigers were exposed in the process of building one submarine and three mini-submarines in Phuket, Thailand.

Murphy also notes the possibility of certain rarer or unprecedented uses of maritime terrorist tactics being used at sea in the future. These include: