Invading an island nation like Japan will not be easy. It would
be more like D-Day or better yet, reference the battle of
Okinawa.
Big budget stuff: full naval and amphibious force with massive air
cover. And worst of all, very heavy casualty for the invading
force.
There are many slightly different casualty figures you can find on
the net for Okinawa, but they are all very high:
"US: 15,900 killed, 38,000 wounded + 26,000 non combat wounded ,
763 planes shot down. JAPAN: 107,000+ soldiers killed, 10,755
surrendered/captured, 100,000+ civilians killed"
"The ferocious hand to hand fighting on Okinawa resulted in 12,281
Americans and 110,000 Japanese killed by June 21, 1945. The
suicidal dedication of the Japanese defenders indicated an invasion
of Japan itself would be costly, with estimates of at least 500,000
potential Allied casualties."
"Total American battle casualties were 49,151, of which 12,520 were
killed or missing and 36,631 wounded... The cost of the battle to
the Japanese was even higher than to the Americans. Approximately
110,000 of the enemy lost their lives in the attempt to hold
"
This is just Okinawa. There was a whole range of other islands the
US had to take before Okinawa in WW2. Names like Leyte, Tarawa, Iwo
Jima etc.
For US Marines and US Army troops in the Pacific, if they survived
one island, they probably get to join in the fight for the next
island. Whoopee.
One figure quoted 500,000 casualty if the mainland of Japan was
invaded. This was WW2 and a very weak Japan in 1945.
So if someone were to mount an attack on Japan today, with today's
modern weaponry involved, the casualty figure would number above a
million surely.
China would be able to absorb a million in human casualties but it
would not be able to absorb the loss in warships and combat
aircraft. After such a huge amphibious undertaking, China would be
very weak.
