New cases of screwworms on July 8 in Veracruz, Mexico has caused the U.S. to close southern borders to livestock imports.

The U.S. has closed its southern border again to livestock imports, saying that a flesh-eating parasite has moved further north in Mexico than previously reported.

In 1932–33, millions in Ukraine starved while Soviet grain rotted in storage. This wasn’t a natural disaster—it was a weapon.