That's not true.
The largest nuke ever dropped on this planet was dropped by the Soviets some time in the late 60s.
So, in essence, the title of the thread ought to be changed to "used on civilians," which is the mistake the US military made. There was no real reason as to why the US military would bomb Hiroshima and Nagasaki, two civilian enclaves. They could've just dropped 16 nukes on military installations and 1) nobody would've been given a shit, 2) the US military would've sent a MUCH stronger stronger message and 3) comparably speaking, the US military would've killed a lot less civilians than the H&N murder spree. Come to think of it, H&N pretty much gave moral basis for ANY Asian country to drop nukes on the US because all they have to do is point to H&N to get many of the Asian country's leader's acquiescence. And don't doubt for a second that the Asian leaders are not aware of the extremely racist tendencies toward Asians of most US military leadership back in the 40s: THEY ARE.
Thank God the plane that was carrying the biggest of the 3 bombs, the one being delivered to Tokyo, was dropped in the middle of the Pacific by mistake.
Heck, the Germans made A MUCH STRONGER case for the US military to nuke them out of existence and yet... the US government brought over nazi scientists, welcomed the nazi's families and took great care when bombing their cities. All because they were like us. Who would've thought that Hitler's family's descendants grew up in Long Island.