“Free and Open Indo-Pacific” (FOIP) is a US foreign policy concept. Its implementation started with President Trump’s administration coming to power and is being actively promoted now. The concept has a strong geostrategic orientation and relies on the largest regional powers of Japan, Australia and India, – the closest partners of Washington in the region. Despite the ongoing differences in setting the priorities of a new regional security structure, members of “Quad” are mostly concerned about China’s growing economic influence and potential military dominance, not only in the Asia-Pacific region, but also in the Indian Ocean. Therefore, the general basis of the Quadrilateral security dialogue in the Indo-Pacific region would be the deterrence of Chinese power and the maintenance of the regional balance of power. The IPR concept is currently at the institutionalization stage. At the same time, the stable trend for strengthening economic, military and political interaction between “Quad” members is continuously developing, regardless of their vision of the framework and the pace of its implementation. In such conditions, the issues of the development of the Indo-Pacific region and the prospects for the further formation of this “Security Diamond” will remain the highest agenda, especially as there are no clear prerequisites for easing U.S.-Chinese tensions. This article analyzes the formation of the IPR as a new geopolitical region, examines changes in doctrinal documents and the dynamics of bilateral relations among “Quad” members, and proposes a forecast for the design of a new regional security system.