Securing Our Arctic Interests Act of 2017 This bill authorizes the department in which the Coast Guard is operating, to enter into a contract or contracts to procure up to six polar-class icebreakers. The Government Accountability Office (GAO) must report to Congress on the cost and procurement schedule for new icebreakers. The Department of the Navy must report to the congressional defense committees on the Navy's capabilities in the Arctic region. The GAO shall transmit a review of such report to such committees. The bill establishes a Deputy Assistant Secretary of Defense for the Arctic Region, who shall oversee: advocacy for U.S. national security interests in the region, mitigation of operational seams to improve unity of effort among the combatant commands with responsibility for the region, identification of any capability and resource gaps in the region and the formulation of plans to mitigate such gaps, identification of actions by foreign nations that increase the threat to U.S. interests in the region and the formulation of mitigation plans, and planning of military-to-military cooperation with partner nations that have mutual security interests in the region. The Department of Defense must report to the congressional defense committees on: (1) the requirements and investment plans for military infrastructure required to protect national security interests in the region; and (2) strategies to improve U.S. communications, domain awareness, and navigational capabilities in the region.