What does "trade men and ground" mean?

[NewHopeR]

Context:

On 25 June 1950, North Korea invaded South Korea, starting the Korean War.[227] The United Nations Security Council passed Resolution 82, which authorized a United Nations (UN) force to help South Korea.[228] The UN empowered the American government to select a commander, and the Joint Chiefs of Staff unanimously recommended MacArthur.[229] He therefore became Commander-in-Chief of the United Nations Command (UNCOM), while remaining SCAP in Japan and Commander of the USAFFE.[230] All South Korean forces were also placed under his command. As they retreated before the North Korean onslaught, MacArthur received permission to commit U.S. ground forces. All the first units to arrive could do was trade men and ground for time, falling back to the Pusan Perimeter.[231] By the end of August, the crisis subsided. North Korean attacks on the perimeter had tapered off. While the North Korean force numbered 88,000 troops, Lieutenant General Walton Walker's Eighth Army now numbered 180,000, and he had more tanks and artillery pieces.[232]

[shannico]

Oops! I think you've left something out...The passage doesn't really make sense.

[Barb_D]

I believe it means that men died and the North Koreans obtained more ground under their control, but the pace of their advance was slowed down.

[NewHopeR]

I believe it means that men died and the North Koreans obtained more ground under their control, but the pace of their advance was slowed down.

Cool.
Thanks

[5jj]

Oops! I think you've left something out...The passage doesn't really make sense.

Nothing has been left out. Barb explained what it meant. Here is a halfway stage, between the original and Barb's version.

All that they (the first units to arrive) could do was trade (= exchange) A (men and ground) for B (time); (as they did this) they fell back to the P.P.

[shannico]

Ok, it wasn't highlighted very clearly though.