What is the meaning of the sentence below? Can we omit "that of" from the sentence?
When China's GDP surpasses that of the US and its nuclear deterrence makes US policymakers .........
Hi, Joshua—"That of" means "the GDP of." China's GDP (i.e., the GDP of China) is being compared with the GDP of the U.S. If the meaning is to be preserved, you can't omit "that of" without making other adjustments.