China is an existential threat to the United States, and Washington needs to slow Chinese momentum and accelerate US technological advances, or fall well behind the Asian giant, witnesses told lawmakers at a Congressional round table on Tuesday.Among the possible strategies needed to counter Beijing’s growing prowess, analysts said, included expanding the Silicon Shield – an attempt to remove China from semiconductor supply chains – to drone and other vital technologies; drastically reducing US bureaucracy; focusing more on emerging technologies like quantum; and countering China’s aggressive bid to create global standards.“China is a systemic rival. It seeks to challenge and…