I think the only thing Western leftists have to offer is withholding their consent for war/conflict.

China's recent changes in Visa policy are interesting. Previously it's been evident that they've been willing to spend zero effort on their pop image in the West, which shows how much difference they think public opinion has on Western government policy. Visa free entry being opened to a swathe of Western countries reflects a change in attitude: maybe they think that a positive Westerner view of China is more valuable now, maybe they think it's easier to push back against "China Bad" propaganda now.

The fact that US and UK are notably excluded from the visa-free policy suggests Beijing sees more potential in Australian and European public opinion.