Battle of Hill 881.

via Wikipedia.

The first contact made with the NVA occurred on Hill 861 when five US Marine forward observers were ambushed in the bamboo, four of whom were killed by gunfire.
After this contact, two companies of Marines advanced on Hill 861, encountering heavy fire from entrenched NVA positions. Constant mortar barrages on potential landing zones prevented evacuation of wounded and fog cut off most air support. Separated, burdened with wounded and dead (it is US Marine Corps tradition never to leave their dead behind), both companies set up hedgehog positions until relieved by other Marine companies.
Even after skinning the hill with napalm, white phosphorus, 500-pound bombs and Huey (helicopter) runs, NVA snipers and machine guns would cut down advancing Marines. Entrenched NVA troops would wait until the Marines were 20-30 yards from their positions, firing on them, bombarding them with 82mm mortars hidden on the reverse sides of ridges and then pursuing them through the burnt trees.
After a constant day and night bombardment, Marine forces managed to take Hill 861, the closest hill mass to Khe Sanh. Dug into the hill they found 400 foxholes and 25 bunkers. The bunkers were often fortified with up to 6 ft of earth and logs, making them all but impervious to the 250- and 500-pound bombs of Marine aircraft.
Having taken Hill 861, the Marine forces advanced against Hill 881 South covered, as they found later, with 10 times as many foxholes and bunkers than 861. Despite the discovery of the well entrenched bunkers on Hill 861; Marine aircraft used 500-pound bombs in the bombardment of Hill 881 South for fear of hitting themselves with shrapnel when they flew low over their targets to avoid monsoon cloud.
With Hill 881 South insufficiently bombarded, Marine infantry found the going even harder than the previous hill, often taking fire from bunkers they had passed, effectively being surrounded on hills and ridges that their own artillery and airplanes had cleared of cover.
After the Marines had suffered heavy losses on Hill 881 South, a new commander ordered the Marine aircraft to break with tradition and use 750-, 1000- and 2000-pound bombs on the heavily-entrenched NVA forces.
With the hills properly bombarded, American forces managed to take Hill 881 North and South in the same day. After beating off a fierce NVA counterattack on Hill 881 North, the Marines could finally claim victory in what had become the bloodiest battle of the Vietnam War so far.

This is one of the most illustrative Battle of the Vietnam war.

*  It highlights the vulnerability of small units.
*  It shows that even overwhelming firepower is no guarantee of victory.
*  It shows the power of the enemy in defense (something never to be underestimated).
*  It illustrates the vulnerability of US forces when faced with effective enemy artillery fire.

But what it mainly shows us is this.

Airpower is NOT enough.

Quick question.

If the B-52s, F-4s, A-4, F-8s, A-7s, Hueys, CH-53s, CH-46s, CH-47s and all the rest of the assembled US firepower was not able to make the enemy turn tail and run, do you think that the V-22 and F-35 will?