I wouldn't say anything about France and it's intentions to sell weapons/technology to china, because it is a "bad country".
Not when the USA has done similar kind of business throughout the years with different countries.
It's real nice of you to sell weapons to questionable countries and then critisize others for doing that

If it'd be up to me, the weapons could be as well ridded all together, but thats not going to happen as long as humans are humans.
Basically theres no reason to not to sell weapons to China, other than that it is a communistic country.
But then again some countries do sell weapons to worse governments than the chinese communists.
So why have these countries, like the USA, sold weapons to these worse governments?
What comes to the USA fightning chinese, it is all about Taiwan, since there are no other reasons why the two would engage in a war.
Keep in mind that Taiwan is not recognized as sovereign country worldwide. Not even by the USA to my knowledge.
Then again it could be also part of Japan, but they renounced their claim on Taiwan.
It has been debatable for a long time whether Taiwan is part of China or not.
Not so surprisingly China considers Taiwan as a part of it and on the other hand that is true, while on the other hand it might not be.
Therefore China has all the right to defend Taiwan as their land and it would be a domestic issue, in which the USA would actually be the invaders.
However the USA doesn't want to consider Taiwan as a part of China.
Therefore Taiwanese matter is not a reason to ban weapons sale to China.
Which is the only reason why the USA would be in a war against the weapons.
Weapons sale to China was stopped after the violent end to the demonstrations, not because of the Taiwan issue.
However I do find it highly unlikely for the USA to enter in a war against chinese.