The United States and China have long been on a collision course in the Asia Pacific, centered around the strategic island nation of Taiwan. Taiwan is currently protected by the U.S., but China considers Taiwan to be a rebellious province, and is determined to reclaim it in the next decade or two. For more than ten years, China and the U.S. have been taking steps in the economic, tech, political and military spheres to prepare for a contest of strength, as each side engages in what are called "salami slicing" tactics  that slightly improve its position (ie: one thin slice at a time, at the expense of its rival) without triggering a war.
This month, in response to the provocative visit to Taiwan by U.S. politician Nancy Pelosi, China took the wraps off its bold new tactic: a series of regular military exercises (which also function as partial and temporary blockades) surrounding the island nation on 6 sides--that can act like a noose. So far, the noose is relatively loose. However, these exercises will be repeated from time to time--and with each provocation by the U.S. and the Taiwan authorities--the noose will tighten.