The World: Hanoi's Rainy-Season Surge

LIKE some cosmic drum roll, the rumble of thunder accompanied the wild winds and torrential rains that swept across most of Indochina last week, heralding the advent of the southwesterly monsoon. From the air, thousands of acres of paddyland glistened in the infrequent sunshine like a vast mirror. By the time the storms abate in October they will have dumped up to 150 inches of rain on the region, turning the ground into a muddy sponge and swelling the majestic Mekong River to flood stage as it courses through Laos, Cambodia and South Viet Nam.

With roads washed out, bogging down allied and Communist troops alike, and with low ceilings grounding helicopters and jets much of the time, the monsoon has traditionally brought a welcome respite to Indochina's battlefields. On the U.S. side, a slowdown in activity was already evident at the beginning of the month as the withdrawal proceeded; in the week ending June 5, American fatalities fell to 19, the lowest seven-day toll since October 1965. Yet U.S. officials in Saigon are particularly concerned as the monsoon season begins this year. In selected areas, Communist troops are not only maintaining the pressure but, despite the rains, seem intent on increasing it.

Though the Communists control very little territory in South Viet Nam, during the past year they have dramatically expanded their control over parts of Laos and Cambodia. In fact, the North Vietnamese army (NVA) now controls more real estate on the borders of Viet Nam than ever before. From the Sino-Laotian frontier in the north to the tiny crossroads town of Snuol in the south, Hanoi's troops are masters of an area that measures 840 miles long and 250 miles wide at its broadest point (see map).

Traction for Trucks. This assures the Communists of access to the Mekong and, most important, provides security for the Ho Chi Minh Trail. Although ARVN (Army of the Republic of Viet Nam) troops, with U.S. air support, inflicted considerable damage during the Lam Son 719 thrust into Laos and made parts of the trail unusable, the Communists reacted by simply moving the key supply network westward and widening it in the bargain. Thus, in recent weeks, Communist activity along the trail has been running at twice the normal rate. U.S. aerial reconnaissance has revealed piles of bamboo and mounds of gravel at many points along the route, indicating that the Communists hope to provide traction for supply trucks no matter how muddy the going gets.

To improve security for the trail, the Communists last month pushed the Laotian army completely off the strategic Bolovens Plateau, deep in southern Laos. Possession of the plateau not only gives the NVA control of the heights overlooking the Ho Chi Minh Trail, but also of a landscape so wild that a full division can assemble there without being spotted from the air. Seeking to further improve their supply network, the Communists continue to battle along Route 23.