Imports from China to the U.S. have cost Americans millions of manufacturing jobs. But building a trade wall around America — as President-elect Donald Trump proposes — will hurt American consumers and U.

The companies have found plenty of new channels to the U.S. market — demonstrating the potential limits of the tariffs Donald Trump has promised to impose.

China banned the export of dual-use products to over two dozen US defence contractors, targeting top players like Lockheed Martin and Raytheon, as it objected to Washington’s latest arms sales to Taiwan.

The move was the latest escalation in the back and forth between Beijing and Washington over products considered vital to national security.

China has imposed sanctions on 10 U.S. defense firms for arms sale to Taiwan, including Raytheon, Lockheed Martin and Boeing Defense. Analysts say the actions are largely symbolic as these companies are already under Chinese sanctions.