Over the next year, three more soldiers from the 1451st  Sgt. Jeffrey Wilson, First Sgt. Roger Parker and Specialist Skip Brinkley  would take their own lives. The four suicides, in a unit of roughly 175 soldiers, make the company an extreme example of what experts see as an alarming trend in the years since the invasion of Iraq.

The number of suicides reported by the Army has risen to the highest level since record-keeping began three decades ago. Last year, there were 192 among active-duty soldiers and soldiers on inactive reserve status, twice as many as in 2003, when the war began. (Five more suspected suicides are still being investigated.) This year’s figure is likely to be even higher: from January to mid-July, 129 suicides were confirmed or suspected, more than the number of American soldiers who died in combat during the same period.

Those statistics, of course, do not offer a full picture. Suicide counts tend to be undercounts, and the trend is less marked in other branches of the military. Nor are there reliable figures for veterans who have left the service; the Department of Veterans Affairs can only systematically track suicides among its hospitalized patients, and it does not issue regular suicide reports.

Even so, stung by criticism from veterans groups and mental health advocates, the Pentagon and the veterans agency have increased efforts to understand and address the problem. They have bolstered suicide-prevention programs, hiring hundreds more mental health providers. At Fort Campbell, in Kentucky, where at least 14 soldiers have killed themselves this year alone, normal activities were suspended for three days in May and replaced with suicide-prevention training. Late last year, the Army commissioned a five-year, $50 million study of the causes of suicide among soldiers, turning to four outside experts to lead the research.

“The ‘business as usual’ attitudes of the past are no longer appropriate,” said George Wright, an Army spokesman. “It’s clear we have not found full solutions yet, but we are trying every remedy.”

Suicide is a complex act, a convergence of troubled strands. Researchers who have examined military suicides find not a single precipitating event but many: multiple deployments, relationship problems, financial pressures, drug or alcohol abuse. If decades of studies on civilian suicides are any indication, soldiers who kill themselves are also likely to have a history of emotional troubles like depression, post-traumatic stress disorder or another illness.

For Jacob Blaylock, the elements of disaster were in place long before he went to war. Still, an examination of his life and death suggests the difficulty of the mission the military has set for itself in identifying and helping soldiers at risk.