How did Trump's 2025 trade war affect the decoupling of US-China supply chains?

Are foreign supply chains that service the US market still decoupling from China? If so, where are the new chains forming, how quickly is the process happening, and why is it unfolding the way it is? This paper provides an initial empirical assessment of the changing nature of product-level sourcing of US imports in the wake of the tariffs President Donald J. Trump imposed in 2018-19 and 2025. It establishes numerous stylized facts. For example, US imports of many consumer electronics--including smartphones, laptops, monitors, and video game consoles--did not decline sharply in 2025 despite US tariffs hitting Chinese production for the first time. Multinational firms had established alternative supply chains in India and Vietnam which they quickly sourced from instead. In contrast, US importers of clothing and footwear did not reorient their supply chains, in part perhaps because the resulting difference between US tariff increases on China and on third countries for those products was too small to motivate them to do so. Finally, much of the longer-term shift of US import sourcing toward Taiwan and Mexico reflected the increasing economic importance of imported inputs for the data center buildout for artificial intelligence, and not strictly decoupling supply chains with China.