D. Importance of having one primary and two secondary targets for each
mission, so that if weather conditions prohibited bombing the target
there would be at least two alternates.
E. Selection of targets to produce the greatest military effect on the
Japanese people and thereby most effectively shorten the war.
F. The morale effect upon the enemy.
These led in turn to the following:
A. Since the atomic bomb was expected to produce its greatest amount
of damage by primary blast effect, and next greatest by fires, the
targets should contain a large percentage of closely-built frame
buildings and other construction that would be most susceptible to
damage by blast and fire.
B. The maximum blast effect of the bomb was calculated to extend over
an area of approximately 1 mile in radius; therefore the selected
targets should contain a densely built-up area of at least this size.