WASHINGTON — Should President Obama decide to send 40,000 additional American troops to Afghanistan, the most ambitious plan under consideration at the White House, the military would have enormous flexibility to deploy as many as 15,000 troops to the Taliban center of gravity in the south, 5,000 to the critical eastern border with Pakistan and 10,000 as trainers for the Afghan security forces.
The rest could be deployed flexibly across the country, including to the NATO headquarters in Kabul, the capital, and in clandestine operations.
If Mr. Obama limited any additional American troops to 10,000 to 15,000, the military would deploy them largely as trainers, with some reinforcements likely in the southern province of Kandahar, the Taliban’s spiritual home. The neighboring, and opium-rich, Helmand Province and the eastern border with Pakistan, military analysts say, would receive few if any American troops and would remain largely as they are today.
Such trade-offs are part of the discussions under way in the West Wing and at the Pentagon as Mr. Obama and his top advisers debate escalating the eight-year-old war. And they drive home the basic point that while the numbers will dominate the headlines, what is really at stake is how to fight the war.
Here is a primer, culled from the diverse views of administration officials and military analysts, on the military utility of some of the force options before the president to bolster the 68,000 American troops already in Afghanistan.
In late September, Gen. Stanley A. McChrystal, the top American and NATO commander in Afghanistan, sent three different troop options to the Pentagon: about 80,000; 40,000 or more; or 10,000 to 15,000. The White House quickly discarded the idea of sending 80,000, making his middle option the high one under consideration by the president.
With 40,000 troops, the military priority would be to deploy as many as 10,000 to Kandahar, the desert province abutting Pakistan; its big city, also called Kandahar, is the second largest in Afghanistan. Currently there are about 3,200 United States troops and 1,600 Canadian soldiers in the area. The Taliban control much of Kandahar Province and are contesting control of the city.
“We do not now have enough troops around Kandahar to secure this area from the enemy,” said Kimberly Kagan, the president of the Institute for the Study of War, who over the summer was part of a team that helped General McChrystal assess the Afghan conflict for the president. Control of Kandahar, the hub of Taliban operations in the south, would be a major strategic accomplishment for the United States military and a psychological blow to the enemy.
An additional 5,000 American troops would probably be sent to the contested Helmand Province, home to the poppy crop that is a major source of income for the Taliban who traffic in opium. The province is the vital breadbasket of Afghanistan, where the river valley is a fertile ground for pomegranates, wheat and other fruits and grains.
Some 4,000 Marines are now in the area, but they have been unable to secure large parts of the province, including guerrilla strongholds in southern and central Helmand.
Yet another 5,000 would probably be sent to the eastern area that some military planners refer to as “P2K,” for the Afghan provinces of Paktika, Paktia and Khost. The three provinces border the mountainous tribal area of Pakistan, including North and South Waziristan. The Pakistani region has become a haven for the senior leadership of Al Qaeda.
“The preponderance of forces, no matter what number you pick, will be in the south, and there will be some in the east,” said a senior defense official, who would not specify further. The relatively stable north and west, he said, “will remain areas of an economy of force.”
Perhaps as many as 10,000 troops would be deployed as trainers with the Afghan security forces, with NATO pledging to send thousands more.
20,000 to 35,000 troops
This way encompasses a number of mid-range options under discussion at the Pentagon and the White House. Defense Secretary Robert M. Gates; Secretary of State Hillary Rodham Clinton; and Adm. Mike Mullen, the chairman of the Joint Chiefs of Staff, have coalesced around a plan to send 30,000 or more troops to Afghanistan, although there are variations in their positions and they are not working in lock step.
The difference between 30,000 and 40,000, military analysts say, is that there might be 5,000 trainers rather than 10,000, and fewer troops to spread flexibly across the country over all, although there would still be a strong concentration in the south.
“Kandahar is pretty crucial, and we should not skimp there,” said Michael O’Hanlon, a national security expert at the Brookings Institution who just returned from a trip to Afghanistan.
Administration officials say that the additional troops would also be deployed to protect some dozen population clusters across the country, including not only Kandahar and Kabul but also Mazar-i-Sharif and Kunduz in the north, Herat in the west and Jalalabad in the east.
Military officials say that three-quarters of any additional troops sent, no matter the number, will be working side by side with Afghan security forces in a “partnering” or apprentice arrangement. They will be separate from American trainers, whose job is to put raw recruits through a basic military training regime.
Under the partnering arrangement, Afghan troops will share the same bases as the Americans, a defense official said, and although there will be separate sleeping quarters and dining facilities, “they’re going to live together, work together, plan together and operate together.”
Should Mr. Obama send 20,000 troops, military analysts say, there would probably be no fourth brigade to use around the country, and parts of Helmand and the east would receive few if any additional troops. With this number, Mr. Obama would expect a greater contribution of troops from NATO allies (about 35,000 troops from other NATO countries are currently in Afghanistan). Much of the American mission would focus on training.
Administration officials estimate the cost of sending 30,000 more troops at $25 billion to $30 billion a year and the cost of sending 20,000 troops at $21 billion a year.
10,000 to 15,000 troops
Under this approach, advocated by Vice President Joseph R. Biden Jr., the United States would accelerate the training of the Afghan security forces and focus on eliminating the Qaeda leadership in Pakistan through drone strikes.
Mr. Obama is likely to announce his new Afghanistan strategy in the first week of December, administration officials say.
Despite the attention to the troop number, Anthony H. Cordesman, a military expert at the Center for Strategic and International Studies, cautioned that it would be about as helpful to understanding the president’s war strategy as counting the number of parts in a Ferrari to determine how it would handle the road.