Lt. Elizabeth Whiteside, a psychiatric outpatient at Walter Reed Army Medical Center who was waiting for the Army to decide whether to court-martial her for endangering another soldier and turning a gun on herself last year in Iraq, attempted to kill herself Monday evening. In so doing, the 25-year-old Army reservist joined a record number of soldiers who have committed or tried to commit suicide after serving in Iraq or Afghanistan… Whiteside’s personal tragedy is part of an alarming phenomenon in the Army’s ranks: Suicides among active-duty soldiers in 2007 reached their highest level since the Army began keeping such records in 1980, according to a draft internal study obtained by The Washington Post. Last year, 121 soldiers took their own lives, nearly 20 percent more than in 2006.