restore trust, manage unresolved territory disputes, and help countries deal with change in the region. In 2013, U.S. officials have begun using the term "Indo-Asia Pacific". In 2019, the United States Department of State published a document formalizing the concept of a "Free and Open Indo-Pacific", to be sustained among members of "the Quad", a partnership of four Indo-Pacific democracies led by the United States, in concert with Australia, India, and Japan. "Indo-Pacific" has also featured prominently in top-level U.S. strategic documents such as the 2017 National Security Strategy, the 2018 Nuclear Posture Review, and the 2018 National Defense Strategy. According to Felix Heiduk and Gudrun Wacker at the German Institute for International and Security Affairs, the concept is aimed at containing China and is "primarily understood as a U.S.-led containment strategy directed against China" in Beijing. It has been argued that the concept of the Indo-Pacific may lead to a change in popular "mental maps" of how the world is understood in strategic terms. The term's profile was raised when it found mention in the joint statement issued by the Indian Prime Minister Narendra Modi and United States President Donald Trump after the former's state visit to the White House on 26 June 2017. "As responsible stewards in the Indo-Pacific region, President Trump and Prime Minister Modi agreed that a close partnership between the United States and India is central to peace and stability in the region. In marking 70 years of diplomatic relations between India and the United States, the leaders resolved to expand and deepen the strategic partnership between the countries and advance common objectives. Above all, these objectives include combatting terrorist threats, promoting stability across the Indo-Pacific region, increasing free and fair trade, and strengthening energy linkages". However, President Trump's November 2017 articulation on Indo-Pacific was widely seen as something that would usher in a new (US–China) Cold War. This led to the Indian Prime Minister spelling out the Indian vision of Indo-Pacific as an enabler for "a common pursuit of progress and prosperity... not directed against any country... (albeit based on) our principled commitment to rule of law". According to Dr. Cenk Tamer, the U.S. seeks to create an "anti-China axis" in the Asia-Pacific region through the conceptualization of the Indo-Pacific because it sees India as a key part in containing China. This was reiterated by President Biden, who declared a "secure and prosperous Indo-Pacific."