No, it's not a separate question at all. The two are inevitably intertwined.
And your beef with China is opium. Marijuana is not opium.
EVERYTHING is being used to expand and increase government power, and by focusing on the single example of the drug war, you are missing the bigger picture and the threat that it comprises.
No, I'm concerned about the rest, too. But this thread is about marijuana legalization.
It's the difference between strychnine and arsenic. One just kills you more slowly is all.
Apart from that, the philosophical underpinnings of marijuana legalization are open ended. As with "Gay" Marriage, if you accept those principles, you will have no defense against more offensive things which will be coming later. (Polygamy, Incest, and lowering age of consent, or in the case of drugs, Crack, Meth, and Heroine.)
Marijuana is just the key to unlocking this door.