Fort Hood is the largest military base in America, has lost more soldiers in Iraq and Afghanistan than any other military facility, and after eight years of constant deployments had more than its fair share of highly stressed soldiers and dependents even before last night's shootings.

In June 2007 The Times was given two days' access to the sprawling 340-square-mile base, which is home to 70,000 people and adjoins the central Texas town of Killeen — an ugly conglomeration of fast-food restaurants, motels and shopping malls with all the usual accroutements of a military town: swathes of low-rent housing, pawn shops, loan sharks and an unmistakable air of transience. Even then the strains of war were obvious.

The 1st Cavalty and 4th Infantry Divisions had already lost 685 men and women, their names recorded on memorials in the two divisions' respective parade grounds and many of the casualties buried in the Central Texas State Veterans Cemetery on a hillside just outside Killeen.

Those names and graves were not the only way of measuring the toll that Iraq in particular was exacting on the base. Paul Dirksmeyer, a chaplain of the 1st Cavalry Division, spoke of the "emotional carnage" — the broken marriages, the mental afflictions of returning soldiers, the frayed nerves of the families left behind, the occasional suicides, desertions and instances of soldiers suddenly running amock.

Major Ben Phillips, a psychologist, estimated that 15 to 30 per cent of returning soldiers had psychological problems, mostly post-traumatic stress disorder or traumatic brain injuries. He said that the soldiers' vulnerability to psychological disorders increased with each deployment, and he equivocated when asked if they were being sent back into action before they were fully recovered.

Wives told of their husbands checking beneath their cars for bombs before leaving for KMart, accelerating under bridges or swerving past old tyres on the road as if they were still in Baghdad. One 32-year-old soldier recalled panicking in a crowded mall one day and laying a man out because "it made me feel I was back in the markets of Tikrit".

Charlotte Graves, guidance councillor at the Smith Middle School on Fort Hood's Tank Destroyer Boulevard, talked of wives being unable to cope alone and cheating on their absent husbands, and of the problems couples faced when the husbands did return. "They are constantly watching their backs. They are constantly on the alert, and the least little thing can set these guys off. They don't tolerate a lot of stuff."

While there were no statistics of marriage break-ups, anecdotal evidence suggested the rate had soared. "It's more like 'Who's still married?," said one soldier. The Army runs an extensive support network for the families of deployed soldiers, with any number of support groups, emergency hotlines, stress workshops, outings and the like. Each is issued with a 126-page Soldier/Family Deployment Survival Handbook. After women who had lost their husbands complained personally to President Bush in 2005, support for bereaved families was greatly improved.

Times Recommends

• James Kilgore's 27 years on the run
• Palin caught with crib notes scrawled on hand
• Hugo Chávez takes to the airwaves – 24/7