I’m just new here guys. And this would be my very first post here in the forums! Please, bear with me. 
I’m just gonna ask you guys what are the objectives of the 1st Marines on Peleliu that they thought it would only last for 2 days but it lasted for 2 months.
The assault on Peleliu represented a failure of American intelligence and consequently tactical planning. The objective was the capture of the airfield, thus preventing the Japanese from using it during the landings at Leyte Gulf, and securing MacArthur’s Eastern flank as he drove into the Philippines. General Rupertus, the Marine commander thought that the naval bombardment would be so effective that the island, just 7 square miles in area, could be secured in just four days of fighting, not two days.
Unfortunately, the Palau archipelago, of which Peleliu was part, had been a Japanese possession since being seized from Germany in 1914, and little was known of Peleliu. The beaches were reconnoitered prior to the landing, but the interior of the island was thought to be made up of gently rolling hills because aerial photos showed this profile. In actuality, the Umurbrogol Ridge, which formed the spine of the island, proved to be a coral/limestone formation that featured steep-sided hills, ridges, gullys and escarpments which had once been the site of extensive mining operations, and were honey-combed with caves, mine shafts and natural rock formations providing excellent defensive terrain. The Japanese knew the US invasion was coming, and had plenty of time to dig deeper and improve the natural caves and mine shafts with interconnecting tunnels and reinforced concrete blast walls to protect the armored cave entrances. The sides of the hills and valley’s were so steep and convoluted that tanks and heavy artillery could not be brought close to engage the targets; every fortress had to be reduced by men with flame-throwers, and bazookas, covered by rifles and machineguns. None of this was apparent until the heavy foliage was blasted away by naval gunfire and by then it was too late to do much about it.
In the event, the airfield at the southern end of the island was captured rather quickly, but the Umurbrogol Ridge overlooked the airfield and the Japanese could direct artillery fire directly onto the field. Instead of trying to stop the invaders at the water’s edge, as was usual for the Japanese defenders, the Japanese commander adopted a sophisticated defensive strategy of making the Marines root out each and every defender and kill them, or seal them in their caves. Since the island was almost as heavily fortified as Iwo Jima or Okinawa, this took time and immense courage (eight Medals of Honor were awarded to Marines on Peleliu). The Marines and Army troops engaged on Peleliu took massive casualties and compared the fighting to some of the worst in their history. Probably the most disturbing aspect of the battle was that it turned out to be unnecessary; The Japanese could not have utilized the airfield, and it could have been safely by-passed and left to wither on the vine. The call was Nimitz’s and it was one of the few significant errors he made in the Pacific war.
A good description of the fighting on Peleliu can be found in “With The Old Breed” by Eugene B. Sledge. Sledge was a Marine who served on Peleliu. Another excellent source for details is http://www.ibiblio.org/hyperwar/USMC/USMC-M-Peleliu/index.html
The assault on Peleliu represented a failure of American intelligence and consequently tactical planning. The objective was the capture of the airfield, thus preventing the Japanese from using it during the landings at Leyte Gulf, and securing MacArthur’s Eastern flank as he drove into the Philippines. General Rupertus, the Marine commander thought that the naval bombardment would be so effective that the island, just 7 square miles in area, could be secured in just four days of fighting, not two days.
Sorry for that mate. 
I love the details. You enlightened my knowledge about the Battle of Peleliu.