Whether we have TNW weapons or not, we are not wise to have not perfected it through tests.
The Chinese will exhaust their nuke stockpile on us and still be able to take out less than 30% of our population but possibly 60% of our economy. The issue is we don't have a retaliatory arsenal that will match those numbers - Too few, too weak.
A deterrent is only credible if it convinces the enemy that a game of attrition will result in a loss for the enemy. Our nuclear policy experts somehow have determined that deterrent is the same as being able to target large civilian populations. This is wrong. How can we base our nuclear deterrence on the assumption that the Chinese are not crazy enough to willingly accept the casualty threshold that we are capable of? They have killed close to 100 million of their own people since 1950, you think they are not nuts enough to take another beating of that scale? And do we even have an arsenal that can deliver those numbers? - probably not, and please lets not get started with cholera will cause death.
On the other hand, the Chinese have a declared arsenal that can wipe out (not just hit, but completely wipe out) the top 100 Indian cities. That is a fact. We have to acknowledge that fact and make a statement that will make the CCP's nuts freeze. The only way to do that would be to test a megaton device but it is unlikely that we will do that. I just hope that our doctrine has built in a ready to test megaton warhead in case hostilities between India and China were to begin. Even before the CCP thinks of a nuclear posture, as hostilities start, on day one we should test it and declare that we enough such warheads to decimate China.
On Pakistan my view is simple - If they fire a nuke, even one, even if our ABM stops it, there should be massive retaliation that takes out all urban populations of more than 100,000 and military/strategic facilities followed by extensive search and destroy missions of all their hidden nuke facilities, storage etc. The country must be split up and we must have boots on the ground there for the next zillion years if need be irrespective of jihadi or whatever threats. I dont care what the world will feel about it how how our nation will be viewed. We are economically strong enough to buy our way outta that kind of shit.