Many nations, including the USSR and Iraq, signed the 1972 Biological Weapons Convention which committed the signers to not develop or use them. Rumors abound that many nations have them, including those weapons that we mentioned. Libya, Israel, China and Taiwan are often mentioned as nations with biological weapons. There are others. North Korea is suspected of having its own stockpile of smallpox viruses.
Rumors persist that it has.
In 1971, several animal and plant diseases mysteriously appeared in Cuba. African swine fever broke out in two places. Blue mold devastated its tobacco crop. Cane smut struck the sugar crop. It is far more expensive for the enemy to care for the sick than bury the dead.