Military security interests, despite their omission from the United Nations Convention on the Law of the Sea, exist in the exclusive economic zone (EEZ) and have been claimed and protected by both the coastal State and other States from different perspectives. All States may conduct military activities in the EEZ for peaceful purposes, including a foreign State, provided that the operating State has due regard to the rights and duties of other States. The coastal State may only challenge the exercise of a military activity by a foreign State if the activity impedes the exercise of its sovereign rights and jurisdiction. This chapter sets out the general rules for conducting peacetime military activities at sea under international law before discussing military security interests in the EEZ. Four types of specific military activities conducted in the EEZ are examined by applying the doctrines for attributing and exercising rights and freedoms between the coastal State and other States. The chapter concludes with a discussion of bilateral and regional practice relating to the conduct of military activities in the EEZ and the potential of these mechanisms to mitigate the controversial interpretation and practice between coastal States and other States.