People were/are worried about fusion bombs for the same reasons they were/are worried about fission bombs, except more so because the yield of a fusion bomb is typically much higher than the yield of a fission bomb. So a fusion bomb typically does more of everything a fission bomb does.
Hydrogen bombs are legal
Yes, America does possess hydrogen bombs
Because it is highly explosive
"Millions of hydrogen bombs"
Atomic bombs, not hydrogen..The U.S. in August 1945.
Of course, hydrogen bombs are real from more than 60 years.
The same nuclear radiation is released by both fission (atomic) and fusion (hydrogen) bombs. Hydrogen bombs are larger, and produce more.
Radioactive fallout
No.
There were no hydrogen bombs (fusion bombs) detonated during WWII.
They never used hydrogen bombs in Japan. They used nuclear bombs which produces gamma rays not the lethal doses of x-rays produced by the hydrogen bomb.
Hydrogen bombs have never been used in war. They have only been exploded in test shots.