Why maintaining ASML equipment is new front in US-China chip war?

The US government has called on allies to force computer chip manufacturing equipment companies to stop maintaining some of the tools they have sold in China, part of Washington’s efforts to undermine China’s ability to produce its own advanced computer chips.

As the largest maker of chipmaking equipment globally, ASML (Advanced Semiconductor Materials Lithography) of the Netherlands is in focus.

Here are questions and answers about the scope of the issue and what is at stake for the US, Netherlands, ASML, and Chinese chipmakers.