“Before deploying here we were given training on language, culture, everything. I thought that since I was an Iraq combat veteran, I didn’t need any of that stuff. I was wrong. Both countries may be Muslim but this is a totally different place,’’ said Sergeant Michael McCann, returning from a patrol in the east-central province of Logar.

While their experiences in the two war zones vary, for many soldiers in the field - if not policy makers - the conflict in Afghanistan is one they think may prove harder and longer to win.

When asked about the many sharp contrasts between Afghanistan and Iraq, soldiers and officers involved in combat operations cite the more punishing geography and climate, those focused on development point to the bare-bones infrastructure, and intelligence specialists note the even greater difficulties in identifying insurgents.

“The sheer terrain of Afghanistan is much more challenging: the mountains, the altitudes, severity of weather, the distances. That wears on an army,’’ said Major Joseph Matthews, a battalion operations officer in the 10th Mountain Division. “You can flood Baghdad with soldiers but if you want to flood the mountains you are going to need huge numbers and logistics.’’

McCann, a military policeman from Enterprise, Ala., says the highest he ever got during his Iraq tour was a five-story building. In Afghanistan, troops routinely cross passes 10,000 feet and higher, descending into valleys where they say villagers “hibernate like bears’’ for up to five winter months, cut off by the snows.

This almost medieval isolation makes it far more difficult for the Afghan government and coalition forces to spread the aid and information needed to counter the Taliban push while the villagers - mostly illiterate and with little access to radios, never mind television - rely on religious leaders at Friday mosque prayers, or the insurgents, to shape their world view.

“When you have a society that can’t read for itself and religious leaders are trusted, they can say whatever they like and people will believe them. It’s hard for the US to penetrate and influence this. In Iraq there are other ways to get the message across,’’ says Chief Warrant Officer Daniel Weiermann Jr., an intelligence specialist, of Fort Hood, Texas.

The US effort in Logar has stressed bridging the chasms among villages, districts, the provincial capital, and a central government in Kabul which has had little control over the country for the past 30 years of warfare. It hasn’t been easy.

“This is not an interconnected society. There is a complete separation of ideas from Pul-i-Alam and Kharwar,’’ notes Matthews, of Vero Beach, Fla., of the provincial capital and a district just 23 miles away. “The difference between a village and a city in this country is about 200 years,’’ says the officer, who served for more than three years in Iraq and is on his second Afghanistan tour.

Although tribalism plays a major role in Iraq, US troops find it even stronger in Afghan society, making the forging of vital bonds between people and government harder. Loyalty is given first and foremost to the tribe, the government coming at best a distant second.

While counterinsurgency in Iraq had its unique complexities, Weiermann said that in Iraq - about 70 percent urbanized as opposed to 25 percent in Afghanistan - “you can meet and hopefully influence a lot of people in one day. In Afghanistan with its great distances, sparsely populated areas, and rugged terrain you can do far less in the same amount of time.’’ Hence, one reason for the prognosis that Afghanistan will be a longer haul.

Development, which absorbs the US military more than combat and is regarded as key to victory, is also far tougher than in Iraq, which already possessed a solid infrastructure. In Afghanistan, at best a quarter of the population can read, compared with more than 75 percent in Iraq, which had functioning banking, medical, and other systems, however imperfect, through which aid could be channeled.