The Malacca strait between Indonesia and Malaysia has long been a haven for pirates. Last year 21 seamen were killed and a further 71 are missing presumed dead following pirate attacks. "We have seen rocket-propelled grenades being fired at the vessel to force it to stop," states Captain Pottengal Mukundan from the International Maritime Bureau. But the biggest fear is of a terrorist attack. "This is a relatively narrow passageway which provides certain operational advantages to the attackers," explains security analyst Brian Jenkins. Mukundan agrees: "You could have a major maritime terrorist incident." The attacks on the USS Cole and The Limburg demonstrate just how vulnerable even warships are to attacks. Analysing the nature of the maritime threat has become a growing industry. But it's not just security analysts taking the threat seriously. Earlier this year, the US suggested sending the marines to patrol the Malacca Strait. The threat was enough to galvanise the Indonesian, Malay and Singaporean navies into action. They're now jointly patrolling the Straits. But whether this will be enough to deter terrorists remains to be seen.