Thank god it has changed with better technology and tactics.
I have always been amazed though at the casualty numbers from the Pacific campaign. We would invade an island with 20,000 fortified, fanatical soldiers and at the end all the 20,000 enemy would be dead and we would have maybe 15,000 casualties including wounded.
I have always heard that you are at a 6 to 1 disadvantage going against a fortified enemy but the marines in wwII defied those odds spectacularly.
Just look at the hardest island Iwo Jima. Nearly 22,000 enemy KIA and we had around 6,800 KIA with 19,000 wounded. That was the only time that American casualties (both KIA and wounded) exceeded the Japanese casualties.