India needs to be more aggressive in defending its territory, but the aggression shall not be for its own sake, Defence Minister Manohar Parrikar said on Monday.Talking to reporters on the sidelines of the Naval Commanders' Conference here, the minister also congratulated the navy for reduction of piracy in the High Risk Area (HRA) of the Indian Ocean."Piracy level has gone down... It will bring down the costs for the shipping industry," he said.Parrikar said that a new maritime strategy document has been prepared by the Indian Navy as the challenges have grown since the last time the strategy document came out."In last eight-ten years, there has been a lot of change in the perspective and challenges... We have to be more aggressive in defending (our territory)...," he said, adding that aggression should not be for its own sake.The minister released the follow-on edition of the Indian Navy's strategic guidance document 'Freedom to Use the Seas; India's Maritime Military Strategy' published in 2007. It would come into effect from December 1.The revised edition is titled 'Ensuring Secure Seas: Indian Maritime Security Strategy', which highlight the incontrovertible link between the seas and India's resurgence in the 21st century.