Seventeen countries have agreed to collaborate on defence strategies for critical marine infrastructure such as undersea cables, an effort that analysts warn may be undermined by the absence of superpower involvement.At the Shangri-La Dialogue in Singapore on Saturday, defence ministers and representatives from these countries attended the launch of the Guiding Principles for Underwater Infrastructure Defence Exchanges (Guide), which aims to bring countries together to explore potential areas of collaboration to enhance security.The 17 nations that endorsed the Guide comprise Singapore, Brunei, Malaysia, the Philippines, Thailand, Australia, New Zealand, Qatar, Estonia, Finland, France, Italy, Latvia, Lithuania, the Netherlands, Sweden and the United Kingdom.China and the United States were notably absent from the list.At the launch, Singapore’s Defence Minister Chan Chun Sing said waterways were not just avenues for trade but also housed critical underwater infrastructure that provided connectivity for energy and telecommunications.“Today, if we are honest with ourselves, we will know that we have quite a lot of work to do to establish the international norms on how we can lay those critical infrastructures … but more importantly, how to maintain them and how to prevent people from disrupting them,” he said.