The Quad are a security alliance consisting of Australia, India, Japan and the United States. They first convened in 2017 with further meetings in the coming years and have regularly engaged in joint-military exercises, especially in the South China Sea. More countries have been looking to ally themselves and partner with the Quad, namely New Zealand and South Korea.
China has actively condemned the actions of the Quad, citing it to be ""NATO imperialist"" and has responded with military exercises of their own.