hmmm, was it really necessary? I noticed US had fatmats and mininukes during the operation anchorage, wouldnt that be a better choice to fight Chinese?
You're dealing with a nation that itself is dealing with a massive resource crisis. All major fuel sources have all but been depleted, and the Fallout Universe (at least the United States) never grasped the concept of Electronic Miniaturization (Personal Computers seem to be a relatively new development).
The T-51b Powered Infantry Armor was a tremendous cost in terms of resources for a resource starved nation. Every one of those suits that was destroyed or lost in China was an investment that would be lost. So the US turned to a potentially more practical solution not only in terms of cost but also to combat the Chinese overwhelming Numerical Superiority (Presuming the Chinese of the Fallout Universe stuck with Chairman Mao's original philosophy of victory through superior numbers in the case of a Nuclear War).
The Deathclaws obviously weren't the success the Government was hoping for, or rather they proved too dangerous to control...or perhaps with the events of Anchorage the situation simply got away from them. Whatever the reason, the bulk of the United States' T-51bs saw deployment in Mainland China while the Deathclaws remained in the United States.
After the Great War, the Deathclaws escaped their confinement and began proliferating around the country. Outside the few suits in the Brotherhood of Steel's posession in California and the two suits that can be found in the Capital Wasteland, it is unknown what became of the bulk of the T-51bs. Presumably, some functional models still exist on the Chinese Mainland. Though the question remains whether or not China is even habitable.