Why attack a fortress when you can starve it? MacArthur's genius was not in fighting battles, but in avoiding them.
Standard military doctrine says you must destroy the enemy force before advancing. MacArthur threw the book away. Facing heavily fortified Japanese positions in Rabaul, he asked a simple question: "Why do we need Rabaul?"
The answer was: We don't. We just need to stop Rabaul from hurting us.
Assault the stronghold. High casualties. Slow progress. "Head-on collision."
Land behind the stronghold. Cut off supply lines. Let the enemy "wither on the vine."
He left 100,000 Japanese troops isolated in Rabaul. They spent the rest of the war gardening and trying not to starve, while MacArthur marched on to the Philippines.
In 1950, North Korea had pushed UN forces to the tiny Pusan Perimeter. Defeat looked certain. MacArthur proposed an amphibious landing at Inchon—the worst possible place to land a fleet (massive tides, mudflats, sea walls).
Because it was impossible, no one defended it.
He severed the North Korean supply lines instantly. The entire enemy army collapsed in days.