Some people spend an entire lifetime wondering if they've made a difference.
The Marines don't have that problem. B-29's during their bombing runs from Tinian Island to Japan, and return. The requirement to silence the early warning emanating from Iwo Jima that told Japan of the B-29s flying toward the home land. Iwo Jima airfields would provide a base for Army Air corps P-51 long range fighters that could escort the bombers to Japan. Many sought this haven because of damage, wounded, or shortage of fuel.