This article was written and reported by C. J. Chivers, Carlotta Gall, Andrew W. Lehren, Mark Mazzetti, Jane Perlez, and Eric Schmitt, with contributions from Jacob Harris and Alan McLean.

A six-year archive of classified military documents made public on Sunday offers an unvarnished, ground-level picture of the war in Afghanistan that is in many respects more grim than the official portrayal.

The secret documents, released on the Internet by an organization called WikiLeaks, are a daily diary of an American-led force often starved for resources and attention as it struggled against an insurgency that grew larger, better coordinated and more deadly each year.

The New York Times, the British newspaper The Guardian and the German magazine Der Spiegel were given access to the voluminous records several weeks ago on the condition that they not report on the material before Sunday.

The documents — some 92,000 reports spanning parts of two administrations from January 2004 through December 2009 — illustrate in mosaic detail why, after the United States has spent almost $300 billion on the war in Afghanistan, the Taliban are stronger than at any time since 2001.

As the new American commander in Afghanistan, Gen. David H. Petraeus, tries to reverse the lagging war effort, the documents sketch a war hamstrung by an Afghan government, police force and army of questionable loyalty and competence, and by a Pakistani military that appears at best uncooperative and at worst to work from the shadows as an unspoken ally of the very insurgent forces the American-led coalition is trying to defeat.

The material comes to light as Congress and the public grow increasingly skeptical of the deepening involvement in Afghanistan and its chances for success as next year’s deadline to begin withdrawing troops looms.

The archive is a vivid reminder that the Afghan conflict until recently was a second-class war, with money, troops and attention lavished on Iraq while soldiers and Marines lamented that the Afghans they were training were not being paid.

The reports — usually spare summaries but sometimes detailed narratives — shed light on some elements of the war that have been largely hidden from the public eye:

• The Taliban have used portable heat-seeking missiles against allied aircraft, a fact that has not been publicly disclosed by the military. This type of weapon helped the Afghan mujahedeen defeat the Soviet occupation in the 1980s.

• Secret commando units like Task Force 373 — a classified group of Army and Navy special operatives — work from a “capture/kill list” of about 70 top insurgent commanders. These missions, which have been stepped up under the Obama administration, claim notable successes, but have sometimes gone wrong, killing civilians and stoking Afghan resentment.

• The military employs more and more drone aircraft to survey the battlefield and strike targets in Afghanistan, although their performance is less impressive than officially portrayed. Some crash or collide, forcing American troops to undertake risky retrieval missions before the Taliban can claim the drone’s weaponry.

• The Central Intelligence Agency has expanded paramilitary operations inside Afghanistan. The units launch ambushes, order airstrikes and conduct night raids. From 2001 to 2008, the C.I.A. paid the budget of Afghanistan’s spy agency and ran it as a virtual subsidiary.

Over all, the documents do not contradict official accounts of the war. But in some cases the documents show that the American military made misleading public statements — attributing the downing of a helicopter to conventional weapons instead of heat-seeking missiles or giving Afghans credit for missions carried out by Special Operations commandos.

White House officials vigorously denied that the Obama administration had presented a misleading portrait of the war in Afghanistan.

“On Dec. 1, 2009, President Obama announced a new strategy with a substantial increase in resources for Afghanistan, and increased focus on Al Qaeda and Taliban safe-havens in Pakistan, precisely because of the grave situation that had developed over several years,” said Gen. James L. Jones, White House national security adviser, in a statement released Sunday.

“We know that serious challenges lie ahead, but if Afghanistan is permitted to slide backwards, we will again face a threat from violent extremist groups like Al Qaeda who will have more space to plot and train,” the statement said.

General Jones also decried the decision by WikiLeaks to make the documents public, saying that the United States "strongly condemns the disclosure of classified information by individuals and organizations which could put the lives of Americans and our partners at risk, and threaten our national security."”

“WikiLeaks made no effort to contact us about these documents – the United States government learned from news organizations that these documents would be posted,” General Jones said.

The archive is clearly an incomplete record of the war. It is missing many references to seminal events and does not include more highly classified information. The documents also do not cover events in 2010, when the influx of more troops into Afghanistan began and a new counterinsurgency strategy took hold.

They suggest that the military’s internal assessments of the prospects for winning over the Afghan public, especially in the early days, were often optimistic, even naïve.

There are fleeting — even taunting — reminders of how the war began in the occasional references to the elusive Osama bin Laden. In some reports he is said to be attending meetings in Quetta, Pakistan. His money man is said to be flying from Iran to North Korea to buy weapons. Mr. bin Laden has supposedly ordered a suicide attack against the Afghan president, Hamid Karzai. These reports all seem secondhand at best.

The reports portray a resilient, canny insurgency that has bled American forces through a war of small cuts. The insurgents set the war’s pace, usually fighting on ground of their own choosing and then slipping away.

Sabotage and trickery have been weapons every bit as potent as small arms, mortars or suicide bombers. So has Taliban intimidation of Afghan officials and civilians — applied with pinpoint pressure through threats, charm, violence, money, religious fervor and populist appeals.

FEB. 19, 2008 | ZABUL PROVINCE Intelligence Summary: Officer Threatened

An Afghan National Army brigade commander working in southern Afghanistan received a phone call from a Taliban mullah named Ezat, one brief report said. “Mullah Ezat told the ANA CDR to surrender and offered him $100,000(US) to quit working for the Afghan Army,” the report said. “Ezat also stated that he knows where the ANA CDR is from and knows his family.” Read the Document »

MAY 9, 2009 | KUNAR PROVINCE Intelligence Summary: Taliban Recruiter

A Taliban commander, Mullah Juma Khan, delivered a eulogy at the funeral of a slain insurgent. He played on the crowd’s emotions, according to the report: “Juma cried while telling the people an unnamed woman and her baby were killed while the woman was nursing the baby.” Finally he made his pitch: “Juma then told the people they needed to be angry at CF [Coalition Force] and ANSF [Afghan National Security Forces] for causing this tragedy” and “invited everyone who wants to fight to join the fighters who traveled with him.” Read the Document »

The insurgents use a network of spies, double agents, collaborators and informers — anything to undercut coalition forces and the effort to build a credible and effective Afghan government capable of delivering security and services.

The reports repeatedly describe instances when the insurgents have been seen wearing government uniforms, and other times when they have roamed the country or appeared for battle in the very Ford Ranger pickup trucks that the United States had provided the Afghan Army and police force.

NOV. 20, 2006 | KABUL Incident Report: Insurgent Subterfuge

After capturing four pickup trucks from the Afghan National Army, the Taliban took them to Kabul to be used in suicide bombings. “They intend to use the pick-up trucks to target ANA compounds, ISAF and GOA convoys, as well as ranking GOA and ISAF officials,” said a report, referring to coalition forces and the government of Afghanistan. “The four trucks were also accompanied by an unknown quantity of ANA uniforms to facilitate carrying out the attacks.” Read the Document »

The Taliban’s use of heat-seeking missiles has not been publicly disclosed — indeed, the military has issued statements that these internal records contradict.

In the form known as a Stinger, such weapons were provided to a previous generation of Afghan insurgents by the United States, and helped drive out the Soviets. The reports suggest that the Taliban’s use of these missiles has been neither common nor especially effective; usually the missiles missed.

MAY 30, 2007 | HELMAND PROVINCE Incident Report: Downed Helicopter

An American CH-47 transport helicopter was struck by what witnesses described as a portable heat-seeking surface-to-air missile after taking off from a landing zone.

The helicopter, the initial report said, “was engaged and struck with a Missile ... shortly after crossing over the Helmand River. The missile struck the aircraft in the left engine. The impact of the missile projected the aft end of the aircraft up as it burst into flames followed immediately by a nose dive into the crash site with no survivors.”

The crash killed seven soldiers: five Americans, a Briton and a Canadian.

Multiple witnesses saw a smoke trail behind the missile as it rushed toward the helicopter. The smoke trail was an important indicator. Rocket-propelled grenades do not leave them. Heat-seeking missiles do. The crew of other helicopters reported the downing as a surface-to-air missile strike. But that was not what a NATO spokesman told Reuters.

“Clearly, there were enemy fighters in the area,” said the spokesman, Maj. John Thomas. “It’s not impossible for small-arms fire to bring down a helicopter.”

The reports paint a disheartening picture of the Afghan police and soldiers at the center of the American exit strategy.

The Pentagon is spending billions to train the Afghan forces to secure the country. But the police have proved to be an especially risky investment and are often described as distrusted, even loathed, by Afghan civilians. The reports recount episodes of police brutality, corruption petty and large, extortion and kidnapping. Some police officers defect to the Taliban. Others are accused of collaborating with insurgents, arms smugglers and highway bandits. Afghan police officers defect with trucks or weapons, items captured during successful ambushes or raids.

MARCH 10, 2008 | PAKTIA PROVINCE Investigation Report: Extortion by the Police

This report captured the circular and frustrating effort by an American investigator to stop Afghan police officers at a checkpoint from extorting payments from motorists. After a line of drivers described how they were pressed to pay bribes, the American investigator and the local police detained the accused checkpoint police officers.

“While waiting,” the investigator wrote, “I asked the seven patrolmen we detained to sit and relax while we sorted through a problem without ever mentioning why they were being detained. Three of the patrolmen responded by saying that they had only taken money from the truck drivers to buy fuel for their generator.”

Two days later when the American followed up, he was told by police officers that the case had been dropped because the witness reports had all been lost. Read the Document »

One report documented the detention of a military base worker trying to leave the base with GPS units hidden under his clothes and taped to his leg. Another described the case of a police chief in Zurmat, in Paktia Province, who was accused of falsely reporting that his officers had been in a firefight so he could receive thousands of rounds of new ammunition, which he sold in a bazaar.

Coalition trainers report that episodes of cruelty by the Afghan police undermine the effort to build a credible security force to take over when the allies leave.

OCT. 11, 2009 | BALKH PROVINCE Incident Report: Brutal Police Chief

This report began with an account of Afghan soldiers and police officers harassing and beating local civilians for refusing to cooperate in a search. It then related the story of a district police commander who forced himself on a 16-year-old girl. When a civilian complained, the report continued, “The district commander ordered his bodyguard to open fire on the AC [Afghan civilian]. The bodyguard refused, at which time the district commander shot [the bodyguard] in front of the AC.”

Rivalries and friction between the largest Afghan security services — the police and the army — are evident in a number of reports. Sometimes the tensions erupted in outright clashes, as was recorded in the following report from last December that was described as an “enemy action.” The “enemy” in this case was the Afghan National Security Force.

DEC. 4, 2009 | ORUZGAN PROVINCE Incident Report: Police and Army Rivalry

A car accident turned deadly when an argument broke out between the police and the Afghan National Army. “The argument escalated and ANA & ANP started to shoot at each other,” a report said.

An Afghan soldier and three Afghan police officers were wounded in the shootout. One civilian was killed and six others were wounded by gunfire. Read the Document »