Chinese propaganda excels at making Americans look like bad motherlovers.

Honestly, good idea. I admire this for outside the box thinking.

I would prefer a belt of nuclear explosion or fallout to encircle the country of my enemy though. Lay waste to all the land and irradiate it better than cobalt does. This could possibly be done while minimizing loss of life also, the collar need not pass through any settlements. 60 years is not so long if you think about it, and the enemy could find ways to clear avenues past the cobalt anyway.

You may ask what would have prevented the enemy’s reinforcements massing and crossing the Yalu in great strength, as they had before. It was my plan as our amphibious forces moved South to spread behind us—from the Sea of Japan to the Yellow Sea—a belt of radioactive cobalt. It could have been spread from wagons, carts, trucks and planes. It is not an expensive material.

“It has an active life of between 60 and 120 years. For at least 60 years there could have been no land invasion of Korea from the North. The enemy could not have marched across that radiated collar I proposed to put across Korea’s neck.

I don't know where he got the idea that this would be feasible. I guess there was so much secrecy around nuclear weapons at the time that even he wasn't cleared to know how they actually work.