The article is confused by contexts. When Trump increased military spending, that was one context. Calling for arms control is a different context. It's all relative.
Anyway, this is the smartest thing he's said so far in his Presidency. Xi and Putin should be glad to come to a mutually verifiable and binding treaty with the US. Putin should make sure that all of the military powers are included. There's no point in only the US, Russia, and China reducing weapons. Frankly, the sanest thing that could happen would be for the whole world to disarm.
The weapons manufacturers would cry, unless the rest of us were to make it worth their while, which we most certainly could do. There are better things they all could be doing with their technical abilities than making weapons and ammunition.