Sen. Jack Reed, a West Point graduate and former Airborne officer who sits on the Armed Services Committee, said after recent testimony by the Army’s top civilian and uniformed leaders that a number of signals — diminished levels of readiness, lower recruiting standards, rising attrition rates among junior officers — point to a watershed moment for the service. The Army has offered bonuses as high as $35,000 to retain officers and noncommissioned officers.

There is “just a feeling that we’re on the cusp, and if we don’t take appropriate action this could become an increasingly complicated and difficult problem,” Reed told reporters during a mid-November news briefing.

Reed argued that the Army must continue to reduce its combat force in Iraq before it can begin to repair the wear and tear from the long stretch of combat.

Along the way, there has also come a sense that, whatever happens in Iraq, the U.S. military budget will continue to increase and the Army may also have more growing to do.

The most arresting fact underscored during Reed’s questioning of Gen. George W. Casey Jr., the Army chief of staff, during a hearing last month was that roughly half of the Army’s 44 active-duty brigades are today rated not ready, by the Army’s own standards. (A brigade ranges from 2,500 to 4,200 soldiers.) Casey, the former commander of ground troops in Iraq, agreed with Reed that this represents “a significant deterioration” since the wars began.

The decline, he stressed, is not in the readiness of soldiers and equipment for their counter-insurgency missions. The troops at war “continue to do a magnificent job,” in Reed’s words. But Casey explained that the ready troops are either in Iraq and Afghanistan or else preparing to go.

“We’re consuming readiness as fast as we build it,” Casey said. In the near term, that means many Army units are not trained and equipped to full readiness in the full spectrum of missions — counterinsurgency aside — they could be called upon to perform elsewhere in the world.

The longer-term consequences for the Army could be worrisome if events in Iraq disrupt plans to reduce troop levels there by tens of thousands in the coming months. That could, in turn, disrupt Casey’s schedule for restoring full readiness and at the same time increase the size of the Army.

Military experts have begun to worry that other vital commodities besides current readiness — for example, money for future weapons and for military family care — are being consumed by the war.

Like much of the debate about the war in Iraq, recent discussions about the Army’s future are colored by history, especially the war in Vietnam, the early aftermath of the Cold War and other milestones in the lives of the people who lead the Pentagon today.

Sen. John W. Warner, R-Va., a senior member of the Armed Services Committee, has noted a paradox: public support for the military is higher than at any time since World War II, but the nation is far from that war’s levels of “sharing of the hardships between the civilians at home” and the military in battle.

Army Secretary Preston Geren III said, at the November hearing on the Army: “All-volunteer force — you know, seven years of war — we’ve never done this before as a nation.”

The draft ended in 1973, late in the war in Vietnam, the last in a series of wars fought with an Army heavily dependent on draftees, and a war that aroused uncommon bitterness in society at large and within the ranks.

The shift to a volunteer Army has been broadly reckoned a success, despite the controversies of the time. “I was a product of the draft and always felt that we wouldn’t be able to sustain the things we’re doing today without compulsory service,” said Sen. James Inhofe, R-Okla., a Vietnam veteran who is one of the staunchest supporters of the war in Iraq. “I was wrong,” Inhofe said, praising the quality of today’s Army.

After the end of the Cold War, the active-duty army had decreased in size by about 300,000 to a low of 480,000 — a mistake, in Casey’s view, that was partially responsible for the Army’s failure to bring sufficient forces and equipment to the invasion of Iraq in 2003. “We were basking in the glow of the great success in Desert Storm, basking in the glow of success in the Cold War, looking around to spend the peace dividend.”

Critics of the Iraq war, including Reed and Armed Services Committee Chairman Carl Levin, D-Mich., tend to focus more on what they deem to have been Mr. Bush’s mistaken decision to invade Iraq.

In any event, there is broad bipartisan agreement today on the importance of a larger, better equipped Army to provide the future defense. Military experts are also pondering a separate but related issue of the volunteer Army’s reliance on large numbers of National Guard and reserve troops in wartime.

“Although it appeared somewhat fashionable to question the relevance of ground troops prior to 9/11, that can hardly be the case now,” Levin said. “The reality of warfare in the 21st century demands both, the high-intensity force-on-force combat that characterized the early weeks of the Iraq war and the grinding, all-encompassing stability and support and counterinsurgency operations” since then.

Levin criticized the administration for coming so late to accept the need for expanding the active-duty Army — something Reed and Sen. Chuck Hagel, R-Neb., an Army veteran of Vietnam, called for early in the Iraq war. This year, Congress and Mr. Bush have agreed to expand the Army by about 65,000 troops to an active duty total of 547,000. Defense Secretary Robert Gates proposed to complete the expansion by 2012, but Casey has accelerated the target date by two years and has suggested that he might favor adding still more troops in the future.

Casey has accelerated the target date for completing that growth, but he has also conceded that his schedule depends on the success of the current plan to reduce U.S. force levels in Iraq. A year ago, there were more than 120,000 U.S. troops in Iraq; the total rose to the current level — between 160,000 and 170,000 — after Mr. Bush ordered a surge to improve security, especially in Baghdad, to help the Iraqi government strike political deals that might improve chances for long-term reconciliation of its contesting ethnic and religious groups.

There is growing agreement in Congress and in the military that, while the surge has helped to score marked reductions in violence, the hoped-for political gains have failed to materialize. Casey and other military commanders have acknowledged a point that Reed has made since the surge began: the surge cannot continue without disrupting established troop rotation schedules that are already badly frayed.

In other words, a return to rotations that are better for Army training, readiness and family life, cannot occur without troop reductions to pre-surge levels. Levin, Reed and other war critics want the administration to turn toward a firm schedule for much deeper reductions — something Mr. Bush has thus far declined to do.

For now, Geren and Casey acknowledge a series of difficulties wrought by the wartime strains. In order to make recruiting quotas, for example, the Army has increased the proportion of non-high-school graduates that it allows to enlist — to more than 20 percent this year from its customary 10 percent or less since the volunteer force was created, according to Michele Flournoy, of the Center for a New American Security.

In addition, a rising fraction of West Point graduates have begun to leave the Army soon after completing their mandatory terms or service, raising concerns, according to Reed, about the quality of the officer corps of the future.

Less evident consequences of the war effort include the delayed training of officers in their specialties — such as tank warfare or artillery — because they have been diverted to the counterinsurgency mission in Iraq.

Casey told the Armed Service Committee that he intends to increase the so-called “`dwell time” at home between combat deployments to at least 15 months. That would permit better training in “full-spectrum” missions, as well as a better quality of life for the soldier.

And, as Joint Chiefs Chairman Mullen was told during his October tour of Army forts, the war’s wear and tear on the fabric of Army family life has been a factor in the decisions of young soldiers and officers to leave the service.

“I am not willing to see the United States military return to the kind of challenges that we had when I was young,” the Army Times quoted Mullen as telling a gathering of Army captains at Fort Sill in October. If military leadership does not figure out how to improve the lot of Army families. Mullen told the young officers, “eventually, we’re going to lose you.”