So long as the soldiers in question are 1) commanded by a responsible officer, 2) wear a fixed insignia/long-distance-recognizable symbol, 3) conduct war operations as per the laws/customs of war, and 4) carry openly, then no, it is not. However, the Taliban wear no insignia, openly wage war against men, women, and children regardless of any military affiliation, and typically hide their weaponry under their robes so as to surprise military units, and therefore are NOT protected by the Geneva Convention. Besides, if the torture of even one Taliban soldier, low or high ranking, saves the life of a "good" soldier or civilian, then it is certainly justified.
Taliban soldiers don't have any real information. Many times they're orders are received by a middleman. If they know nothing, why torture them, going against the Geneva Convention? They are only following orders. If they did not, they themselves would have been murdered by the rest of the group, along with they're families.
1. The word 'terrorist' is arbitrarily used. Afghanistan did not have the finances to fund an army with insignias, but that does not make them any less of a nationalistic defense force. So the Geneva stipulations are not applicable, and were designed for dictating prisoner rights between warring nations, not guerrilla fighters.
2. Insurgent organizations have "officers", the effort to capture these men is often cited as the reason for the enhanced interrogations.
3. The intelligence community has been unable to demonstrate a single example of information gathered through enhanced interrogations later saving American lives or resources.
4. American drones kill women and children, are our soldiers also fair game for torture? Certainly not, yet we will not afford those we capture the same respect we demand?
5. American intelligence operatives often hide their weaponry.
6. America went to war because Saddam "was an evil, evil man" with WMDs. He is evil, because he tortured and killed masses of people.
By my last count, over 300,000 Iraqis lost their lives due to our attack. By our own logic, and the fact we actually possess and have used WMDs, the fact that we torture our enemies, and kill civilians, our soldiers are just as guilty as the average Taliban grunt.
America, has been touting our moral superiority for neigh on 60 years. It's time we lived up to our own expectations.