In a trade war with China the American sectors that could easily face retaliation from the US are, energy, ag, pharma.
On the whole, though, China’s major point of leverage is less on what it buys from the US than on what it sells. The obvious candidates here are a range of minerals crucial for industrial—and especially military—production, notably rare earths, gallium, germanium, antimony and highly-refined graphite. For virtually all of these critical minerals US import dependence is at least 80%, and China’s control of global refined production is typically well north of 60%—and in the case of gallium, germanium, rare-earths and high-end graphite, over 90%.
Source: Gavekal