U.S. American President Donald Trump announced – during his first Asia tour in November 2017 – that it was now time to think about the Indo-Pacific strategy. This has de facto put an end to Washington's previous Asia-Pacific strategy adopted by Trump's predecessor in 2011: the U.S. "pivot to Asia". This shift increases the chances of recreating what has been known as the so-called 'Quad', that is, an alliance which comprises the US, India, Japan, and Australia.
China, which is deeply involved in the region, especially through the BRI (Belt and Road Initiative) is now thinking about how to respond at the strategic level, even if it is probably still too early to draw conclusions about what China's Indo-Pacific strategy will encompass. However, there are already visible elements, which enable us to understand how the Chinese Indo-Pacific strategy might look like.
First of all, China's ports expansion policies deserve a critical analysis. Intertwined with the BRI, China has already consolidated its presence in the ports of Djibouti in the Horn of Africa, Gwadar in Pakistan, Hambantota in Sri Lanka, in the Maldives, and in Tanzania.
The strategic reason for China's ports expansion policies throughout the region is twofold. First, China needs to protect its supply routes – that is, the sea lines of communications (SLOC) – destined for its own economic development. To be able to achieve this objective, for years now China has been engaged in a naval military growth aimed at both the construction of a navy capable of performing military as well as humanitarian operations outside China's coastal areas and at the protection of its trade interests, especially in light of growing regional tensions with the United States and India. The necessity to move now into the military realm is a "reverse of the Mahanist idea of commercial ships following the warships." 
It is clear that, for Beijing, the protection of trade routes is motivated above all by the need to meet the goals of its economic growth. For instance, 80% of the oil Beijing imports passes through the Indian Ocean and the Strait of Malacca before it reaches the South China Sea. For China, therefore, the Indo-Pacific routes are vital corridors (生命线– shengming xian) for its energy survival. It is essential, then, to be able to defend them against possible adversaries. For example, a naval blockade in the Strait of Malacca, in Southeast Asia, which would halt the supply of crude oil for China, would have an immediate negative impact on the Middle Kingdom's domestic stability. This concern had already been expressed in 2003 by the then Chinese President Hu Jintao who referred to the "Malacca Dilemma" (马六甲困局–maliujia kunjun) when talking about the so-called chokepoints of Southeast Asia.
This geopolitical commitment underlines China's historical geographical vulnerability: long maritime and land borders to protect against adversaries. For instance, Beijing’s economic decade-long rise has paved the way for the establishment of the so-called first and second "island chains", which are conceived as means to contain China's territorial and military expansion in the region. Therefore, one of the major drivers of China's ports expansion policies concerns Beijing's desire to minimize its maritime vulnerability and to shorten its supply routes; in other words, finding a way to diminish the so-called "tyranny of distance."  In so doing, China is trying to establish its presence (both military and otherwise) in various ports along the Indian Ocean in order to protect its maritime corridors. The way Beijing is expanding its presence abroad also highlights another important feature of China's ports expansion approach, the so-called dual-use strategy, namely the use of ports for both civilian and military purposes.
The second reason behind China’s ports expansion concerns Beijing's desire to extend its own influence throughout the region both to fulfill its hard and soft power objectives. For example, it was recently announced that the Middle Kingdom might be willing to establish a military post in Vanuatu, a tiny republic located outside the Indo-Pacific region. Since this outpost lies outside China's historical areas of geopolitical interest, it is clear that such a move responds more to Beijing's overall objective to extend its presence throughout the region than to its own intimate necessity to protect the sea lines of communication. In fact, such a Chinese base outside the Indo-Pacific would create favorable conditions for checking on Australia's maritime moves and policies, especially in light of Canberra's involvement in what may be the revival of the above-mentioned Quad, i.e. the four-party alliance between Japan, India, and the United States. At the same time, this action would further enhance Beijing's ability to monitor US actions in Guam.
The second element, a direct result of the first, concerns China’s new maritime strategy, which also encompasses the Indo-Pacific. The most valid explanation is offered by the 2015 China's Military Strategy White Paper. It illustrates Beijing's plan to develop a blue-water navy fleet, able to carry out operations for offshore protection (远海护卫 – yuanhai huwei). The document has also labeled the offshore protection as "frontier defense", that is, the protection of the new Chinese frontiers abroad directly related to Beijing's own national and security interests. This stands in contrast to Chinese classic defense operations, carried out near the coast (近海防御 –jinhai fangyu), for which China's coastal fleet (green-water navy) would have been already sufficient. The creation of a blue-water navy is crucial according to the new national defense document, since it highlights the importance of moving from one maritime theater of operation (the Pacific Ocean) to two (the Pacific and the Indian).
Moreover, this strategic shift also entails the so-called "1.5 war" doctrine, which calls for the development of Chinese naval capabilities able to fight one major war while being able to contain a second military conflict. In other words, China is trying to find a way to be able to fight in the East or South China Sea against, for instance, the US, while also facing the possibility of an Indian attack on its land frontier or vice versa.
The creation of a high seas fleet would facilitate the expansion of the Chinese military presence at the regional and global levels and would help Beijing to counter India and the United States' encirclement policies. Taking New Delhi into Beijing's strategic calculation, China is creating, in the Indian Ocean (Sri Lanka, Maldives, Pakistan and Bangladesh), what has been defined as the strategy of the "pearl chain" (珍珠链 – zhenzhulian), not be mistaken as the so-called "string of pearls" which simply envisages the creation of logistical support points in the Indian Ocean. The pearl chain, instead, entails the policy to connect the main strategic ports of the Indian Ocean – even through the physical control of the strategic islands –in order to form a combat-oriented containment line of India. New Delhi, under the Modi presidency, has launched an intense program of military modernization. The Indian navy is expanding into what the government perceives as its area of influence. The fruits of India's new assertiveness already manifested themselves in 2017, first by sending its own military unit to the Strait of Malacca, with the aim of monitoring the commercial flow of the area, and then through the military standoff with China on the Doklam plateau, located between Bhutan, India and China – clear indications of Indian preparedness to deter the above-mentioned Chinese maritime expansionism.
As a result, Beijing's crucial aspects of its developing Indo-Pacific strategy - ports expansion and blue-water navy – are two assets to be closely monitored for the future strategic interaction within the region. The ports, in fact, are considered strategic support points (战略支点–zhanlue zhidian), in order to both protect the maritime routes for the transportation of the necessary resources for Beijing's economy and to extend the Chinese influence at regional and global levels. Chinese influence that could also be the result of a more assertive foreign policy, which tries to find a way to deter other countries from what Beijing perceives as "encirclement policies" against it.
 You Ji, “China’s Emerging Indo-Pacific Naval Strategy”, Asia Policy, 22 (2016), p. 14.
John W. Garver, Diverging Perceptions of China’s Emergence as an Indian Ocean Power, Asia Policy, 22 (2016), p. 56.