With Retreat Comes Great Vulnerability

WASHINGTON —  Israeli forces pulling out of southern Lebanon are learning firsthand what armies have been finding out for centuries: Withdrawals can be the riskiest of military operations.

As American troops discovered in Vietnam in the 1970s and the Russians in Afghanistan in 1989, a military withdrawal throws forces into positions of great vulnerability.

They can be harassed and ambushed, even by far smaller forces. They face a tough job supplying and defending their rear-guard forces, which grow smaller as the withdrawal continues.

And there’s a dangerous difference in strategy and morale: Withdrawing forces are typically cautious and want to risk no losses, while advancing troops are feeling triumphant and often want to inflict maximum casualties on the departing foe.

For these reasons and others, U.S. Army instructors teach their classes that withdrawals tend to be more risky than offensive or defensive operations, said Richard J. Dunn, a retired Army colonel who helped advise South Vietnamese forces as U.S. troops pulled out of Vietnam.

“You’re at tremendous tactical risk,” Dunn said.

In recent days, the Israelis have found out how difficult it is to execute an orderly withdrawal, even with planning and a huge advantage in strength.

As they have given up territory in a 9-mile-deep “security zone” in southern Lebanon, the allied militia they left behind has crumbled. Hezbollah guerrillas have swept victoriously through village after village, moving close to the Israeli border.

And though it was planned to last until early July, some analysts believe that the entire withdrawal could be over in days.

In 1842, the mighty British army learned about the difficulties of retreat after invading Afghanistan and occupying territory all the way to Kabul, the capital.

When the force of 4,500 British and Indian troops and 12,000 civilians marched out, they were attacked by Afghan fighters, who killed hundreds on the road, and then, in a massacre at the Khyber Pass, left no survivors except the regimental surgeon.

Rudyard Kipling, the chronicler of British imperialism, later wrote a poem advising troops that when they fought in Afghanistan to remember to save their last bullet--for themselves.

Russian forces had a similar experience when they withdrew from Afghanistan in early 1989, after their troubled 10-year occupation.

The 50,000 Russian troops who occupied the area around Kabul were nearly surrounded and faced regular rocket attacks. When they mobilized to withdraw, they were threatened by Afghan fighters from ambush sites that dotted the road leading through the Hindu Kush mountains toward the Soviet Union.

U.S. forces also had an unhappy experience when they withdrew in the early 1970s as part of their plan to leave South Vietnam to be defended by the South Vietnamese military.

In March 1972, with 6,000 American combat troops and 63,000 noncombat troops remaining, Defense Secretary Melvin Laird told Congress that a major assault by the North Vietnamese and Viet Cong was “not a serious possibility.” The Pentagon advised that enemy forces were not likely to have any staying power if they did attack.

Yet on March 30, 1972, 120,000 North Vietnamese regulars and thousands of Viet Cong guerrillas unleashed a ferocious nationwide offensive that lasted until June and temporarily swamped the defenders. The North Vietnamese concentrated their attacks on strategic points, while the South Vietnamese forces were thinly stretched trying to defend the entire length of their nation.

The South Vietnamese, with important American air support, kept fighting for another three years. Yet the North Vietnamese believed their offensive had made the point that they would soon be the victors--and that the American “Vietnamization” plan was doomed to failure.