Fort Irwin: The training area testing armoured units to the edge of failure
With its 12,000 square miles of brutal terrain, Fort Irwin National Training Center tests armoured combat units to the edge of failure.
Located in southern California, it is the US Army's largest training centre and is so big that Salisbury Plain could fit inside it eight times.
Forces News visited the NTC to find out how it all began.
'Be ready for the first fight - because you might not survive to the second'
"We were created back in the 1980s as a result of the 1973 Yom Kippur War," Brigadier General Curtis D Taylor, the Commanding General of the National Training Center, told Forces News.
"We were coming out of the Vietnam War at the time. We sent a lot of army leadership over to study that conflict and try to understand what lessons could be drawn from the change of character of war from the Yom Kippur conflict."
On 6 October 1973, war erupted in the Middle East as Egypt and Syria launched a surprise attack on Israel during the Yom Kippur holiday, starting a nearly three-week conflict that would become known as the Yom Kippur War.
Brig Gen Taylor said two key points emerged, technology moving very quickly, in many ways catching the Israelis off-guard, and the growing number of tank-on-tank engagements.
"Because tank engagements were so lethal in Yom Kippur, you could lose your entire army, or a significant portion of your army before you had time to adapt," he explained.

Fort Irwin NTC prepares military units and personnel with realistic pre-deployment training scenarios in all aspects of armed conflict.
Brig Gen Taylor added: "What saved the Israelis was their investment in training. They had really worked very hard to invest in a high-quality training programme, which made them much more adaptable to surprise.
"They were able to anticipate surprise."
He said the big lesson learned from the Yom Kippur War and the Vietnam War, where the US Navy had invested in air-to-air combat training, was "training really matters".
"You'd better be ready for the first fight - because you might not survive to the second," he warned.

A 'complex' battlefield
"The battlefield is so much more complex," Brig Gen Taylor explained, giving the example of how using a mobile phone could give away someone's position to the enemy.
"The battlefield is now very much a thinking man's game, because of the amount of capability that your enemy has to see and detect you in virtually any spectrum that's available."
The NTC will continue to adapt its training scenarios to reflect current conflicts, while trying to anticipate emerging threats.
He added: "The constant vigilance that a soldier must have to ensure they are not being detected and if they are detected that their activity isn't understood for what it is, but it is perceived to be something more benign.
"That's a very important lesson we try to teach. So we need the very best of our nation to continue to be part of the military because this is very complex."