Long term a trade war will not enable the US to maintain a lead when that very thing stimulates the Chinese to try harder to produce sanctioned goods at home while the Chinese are also promoting greater innovation. If America wants to stay ahead it's a case of 'Must try harder'.
Unlike the US, China can also encourage research that doesn't necessarily produce any immediate return on investment while using people who probably would have been conducting research for US companies and universities if not for the limiting of foreign workers.