In 1965, the U.S. military in South Vietnam began conducting what officials called harassment and interdiction missions, or “H and I” fire. Harassment and interdiction fire involved the shelling, by artillery and mortars, of known or suspected areas of Communist activity. In Quang Ngai, where the Vietcong controlled most of the countryside, that meant almost the entire province.
The bulk of H and I fire fell on river crossings, footpaths, trail junctures, gullies, ridgelines, and where river valleys left the highlands and entered the coastal plain. These landscape features acted as North Vietnamese and Vietcong lines of communication. American artillery batteries also regularly shelled the likely approaches to the U.S.’s divisional bases, fire support bases, and night defensive positions.
Occasionally, H and I fire was truly random, striking a rice paddy, a river bank, a grove of trees, or a hamlet. American commanders justified H and I fire on the grounds that it kept the enemy off-balance, deterred Communist troop movements, terrorized the Vietcong, and enhanced the defenses of U.S. and South Vietnamese bases. Like the intensive U.S. aerial bombardment of the South Vietnamese countryside, H and I fire became a ubiquitous feature of the Vietnam War. The U.S. never abandoned its use, even though its effectiveness as a counter-insurgency tactic became increasingly suspect.
By late 1967, the United States had fired millions of artillery and mortar rounds into the South Vietnamese countryside in direct support of combat operations or as H and I fire. At the time, it was estimated that eighty-five percent of all U.S. shelling was unobserved fire – or H and I.
The expenditure rate of the artillery batteries at Duc Pho, Quang Ngai Province, provide an example of the astronomical number of shells expended across rural South Vietnam. In a three-and-a-half-month period in 1967, the Duc Pho batteries fired 64,044 shells. This was the expenditure rate at a single fire support base.
At the end of 1967, there were almost sixty U.S. artillery battalions in South Vietnam. And each of those battalions possessed eighteen howitzers divided among several batteries. Each battalion’s batteries frequently conducted operations independently of one another. For example, an artillery battalion often had its eighteen guns split up and deployed as a two-gun, four-gun, or six-gun battery. This meant that by the close of 1967, American artillery batteries conducted operations at hundreds of fire support bases.
The batteries scattered across South Vietnam fired comparable amounts of ammunition as the guns at Duc Pho. William Ehrhart, who served with the Marines in I Corps in 1967, recounted, “It was never really silent in Vietnam. Night after night, all the way to the four horizons, 360 degrees around, there was color and sound all night long: the flash and boom of artillery from three batteries at battalion and the flashes from dozens of batteries elsewhere….”
The high number of shells falling from the sky at all hours of the day and night made normal life impossible for the peasants in areas subjected to the shelling. Rural South Vietnamese learned that at certain times of the day they needed to be near a bomb shelter or they risked being caught out in the open and killed by incoming shells. The simplest of daily chores, such as going to a stream to gather water, herding water buffalo across a pasture, or preparing a rice paddy for planting could result in death from a surprise artillery barrage. While H and I fire terrorized the peasantry, it had far less of an effect on its intended target, the Vietcong, because the guerrillas could hide deep inside tunnels, seek refuge under triple canopy jungle, or flee to remote base areas – actions the average peasant could not take, especially women, young children, and the elderly.
Ngo Thi Thi, who lived in a hamlet north of Kim Son, Binh Dinh Province, told UPI reporter Tom Corpora that she lived in constant fear because of American artillery shelling: “It’s sad…Just the noise all the time. Every time it [an artillery piece] goes off we don’t know whether it will come in here or not. When we go to bed we do not know whether we will wake up in the morning.” Her wartime experience of life in rural South Vietnam was the norm for millions of peasants.
Harassment and interdiction fire complicated the job of rural pacification. A study done by the Defense Department in July 1967 stated, “…our unobserved fire alienates the local peasants in most cases, thus harming our efforts to break down their loyalty to, and support for, the Viet Cong.” This assessment contrasted sharply with an earlier conclusion of the Rand Corporation, which had argued that the U.S. could bomb and shell the countryside with impunity, since the peasantry would blame the Vietcong for the destruction.
After the war, Douglas Kinnard surveyed U.S. military officers about the use of H and I fire. Respondents were highly critical of it. One officer went so far as to label the practice “madness.” Yet, despite the evidence against its use, and the muted opposition of subordinate officers, General William C. Westmoreland considered the tactic necessary and beneficial. He never abandoned the practice nor did he make any effort to slacken the rates of ammunition expenditure.
Artillery batteries across South Vietnam possessed a variety of different weapons, two of the most common were the M-102, 105-mm howitzer and the M2, 155-mm “Long Tom.” An M-102 shell had a range of about seven miles, while the M2 could lob a ninety-five-pound shell nearly fifteen miles. In consequence, the artillery gunners carrying out H and I missions rarely saw firsthand the destruction that poured forth from their guns, which meant that the reach of America’s artillery shells created a distance between the actions of the warriors and the destruction of their actions. This physical distance, and its resultant emotional distance, perpetuated the ruin of rural South Vietnam.
 New York Times, “Airmobile Force Called Ideal to Combat Counter Insurgency,” Hanson Baldwin, December 12, 1965.
 Douglas Kinnard, The War Managers: American Generals Reflect on Vietnam, (New York: Da Capo Press, 1991), 47.
 U.S. Congress, Senate, Committee on the Judiciary, Subcommittee to Investigate Problems Connected with Refugees and Escapees, “Hearings Before the Subcommittee to Investigate Problems Connected with Refugees and Escapees of the Committee on the Judiciary, United States Senate,” May 10, 18; August 16; September 21; October 9, 10, 11, 13, and 16, 1967, U.S. Senate, 90th Congress, 1st Session. (Washington, D.C.: GPO, 1968), 145.
 Jonathan Schell, The Military Half: An Account of the Destruction in Quang Ngai and Quang Tin, (New York: Alfred A. Knopf, 1968), 32.
 Vietnam Task Force, Office of the Secretary of Defense, The Pentagon Papers, Parts IV.C.6 through IV.C.8, “IV.C.6. (b), U.S. Ground Strategy and Force Deployments, 1965-1967, Volume II,” (Nimble Books LLC, 2011), 111.
 W.D. Ehrhart, Vietnam-Perkasie: A Combat Marine Memoir, (Amherst: University of Massachusetts Press, 1995), 40-41.
 John Laurence, The Cat from Hue: A Vietnam War Story, (New York: Public Affairs, 2002), 351.
 Andrew Krepinevich, The Army and Vietnam, (Baltimore: John Hopkins University Press, 1988), 201.
 Kinnard, The War Managers, 47.