WASHINGTON — Army leaders are expressing increased alarm about the mental health of soldiers who would be sent back to the front again and again under plans that call for troop numbers to be sustained at high levels in Iraq for this year and beyond. Among combat troops sent to Iraq for the third or fourth time, more than one in four show signs of anxiety, depression or acute stress, according to an official Army survey of soldiers’ mental health. The stress of long and multiple deployments to Iraq is just one of the concerns being voiced by senior military officers in Washington as Gen. David H. Petraeus, the senior Iraq commander, prepares to tell Congress this week that he is not ready to endorse any drawdowns beyond those already scheduled through July. President Bush has signaled that he will endorse General Petraeus’s recommendation, a decision that will leave close to 140,000 American troops in Iraq at least through the summer. But in a meeting with Mr. Bush late last month in advance of General Petraeus’s testimony, the Joint Chiefs of Staff expressed deep concern about stress on the force, senior Defense Department and military officials […]