Ten years after the last large scale piracy attacks in the Western Indian Ocean, other maritime crimes such as illicit fishing and maritime smuggling have emerged. The spill over of conflicts in Yemen and Mozambique and maritime grey-zone activities have also become major maritime security issues. Yet, perhaps the most worrying – though largely underappreciated – trend is the surge of naval activity and strategic competition in the region. This is a major dilemma for the region: The region relies on external military actors to protect vital shipping lanes, but the presence of these actors also risks importing geopolitical tensions that could undermine regional maritime stability. How can the region address these maritime insecurities and the evolving militarisation dilemma? We investigate the regional maritime security architecture to identify institutions that can help the region manage the militarisation dilemma. We argue that only the Shared Awareness and Deconfliction (SHADE) mechanism and the Contact Group on Piracy off the Coast of Somalia (CGPCS) can help mitigate geopolitical competition in the region. Preparing these mechanisms to deal with the militarisation dilemma will be vital for the long-term prosperity of the Western India Ocean.