Various news reports say that Hamas is releasing incendiary balloons from Gaza, apparently trying to set Israeli forests on fire. Of course, that brings to mind the Japanese WWII balloon bombs where they tried to do the same to North American forests. I don’t recall any other cases of unmanned balloon warfare. Have there been any?
The British used them against Germany in WWII. It was considered a successful operation only in that it caused economic damage to Germany. Mostly the operation involved trailing wires from balloons to disrupt power lines but the incendiary ones were used to start wildfires.
The Japanese timed their incendiary balloon releases to coincide with maximal jet stream winds toward the U.S., in November-March. Fortunately this coincided with maximal precipitation in the Pacific NW which greatly lowered the chance of fires.
The Japanese were also hoping to hit industrial targets and kill people (there were 6 deaths in one incident). One balloon short circuited a power line feeding the Hanford nuclear facility but they were able to get backup power to the reactor cooling pumps.
This video by the ever excellent Mark Felton covers Operation Outward and contains some great archival footage.
Thanks for the info on Operation Outward. I was totally unaware of that. And it was much more of a success than the Japanese operation. Following a link at that page, I find that the Austrians tried to use balloons when besieging Venice in 1849. That was largely unsuccessful.
Not so much forests (there aren’t many in the area), but rather farmland.
If you count propaganda warfare, there have been balloon launches from South Korea into North Korea.