It's bad enough that China has occupied the Galwam Valley, but to add injury to insult, they've beaten to death 20 of our personnel. This cannot go unanswered. China must be repaid in full and the lost territory re-taken. To back down now, is to embolden an already aggressive predator.
In addition to this, India must impose tariffs on all Chinese goods and services. Every Indian must bear the cost of doing business with China. China's inroads into Nepal must also be countered, or it will lead to the gradual Sinification of our closest neighbor.
If Modi can't do anything, then he needs to hang up his nationalist coat, and say "not a blade of grass grows there." He can't expect people to be sacrificing their lives for a cause he won't truly back.
As we can see, the "peaceful rise of China" is a farce - how easily their mask slips off. All of China's neighbors are currently on the receiving end of aggression by it.
The biggest beneficiary of any war would be Xi. Face with a worldwide backlash against his govt over Coronavirus, Xi is trying to stoke up multiple conflicts all around China's periphery, hoping that at least one of these gambits will pay off and give him a war - a war which he can use as a distraction to rally his people around his floundering regime.
But India has no choice.If China is allowed to get away with it this time, then they'll be sure to do it again - and next time they'll do worse.