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 the northern province of 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, or 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 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 that 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, illustrates the astronomical number of shells exploding 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 artillery battalions in South Vietnam posted to hundreds of Fire Support Bases (FSBs). Each artillery battalion usually possessed eighteen howitzers evenly divided amongst three batteries.
The hundreds of batteries scattered across South Vietnam likely fired comparable amounts of ammunition as the base 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 chanced 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.
H and I fire complicated the job of rural pacification. A study done by the Defense Department in July 1967 concluded, “…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 conclusion contrasted sharply with the 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. 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 mounting 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 long 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.