China
The most significant actions Biden could take on China in his first 100 days would not relate directly to China. Restoring American leadership in tackling global challenges, repairing relationships with allies and partners, countering the spread of Covid-19 at home and abroad, reviving an economy slammed by the pandemic — any of these steps would disprove Beijing’s belief that America has lost its capacity for self-correction.
Concerns about a rising China's behaviour has been a key driver of US-India relations since the mid-2000s. One of the reasons India and the US have come together has to do with concerns about certain kinds of Chinese behaviour, not China per se. These concerns range from China unilaterally changing the status quo in the region, Chinese economic behaviour, and its impact on the rules-based order in the region. In terms of a broader US-India relationship, that has been a key factor, though not the only factor.