Nukes, in the general sense, also cause massive destruction of an area and make it uninhabitable for long periods. The "targeted" use of bioweapons (in theory) allows for the clearing of people sans the mess and down time.

I'm pretty sure that that is common knowledge and openly discussed among people who care about such stuff.

> The United States (and allies) have already used rain seeding, river damns, and a number of other techniques for damaging adversary nation's economic and agricultural abilities.

Would you provide more information in the form of a reliable source?

"Operation Popeye (Project Controlled Weather Popeye / Motorpool / Intermediary-Compatriot) was a highly classified weather modification program in Southeast Asia during 1967–1972. The cloud seeding operation during the Vietnam War ran from March 20, 1967 until July 5, 1972 in an attempt to extend the monsoon season." [1]

"After World War II, the U.S. military bombed dams in North Korea and North Vietnam to destroy the communist governments’ electricity and irrigation infrastructure. This was, until the Iran-Iraq War, the final occurrence of such soggy tactics. In 1977 the Geneva Conventions specifically outlawed the targeting of water infrastructure in wartime." [2]

[1] https://en.wikipedia.org/wiki/Operation_Popeye [2] https://medium.com/war-is-boring/dam-warfare-3da6ee24518a https://en.wikipedia.org/wiki/Bombing_of_Vietnam%27s_dikes