Vietnam War

==Weapons==
{{Main|Weapons of the Vietnam War}}
[[File:HoChiMinhTrail003.jpg|thumb|upright|left|Guerrillas assemble shells and rockets delivered along the Ho Chi Minh Trail.]]

During the early stages of the war, the Viet Cong mainly sustained itself with captured arms; these were often of American manufacture or were crude, makeshift weapons used alongside [[shotgun]]s made of galvanized pipes. Most arms were captured from poorly defended ARVN militia outposts. In 1967, all Viet Cong battalions were reequipped with arms of Soviet design such as the AK-47 assault rifle, carbines and the [[RPG-2]] anti-tank weapon.<ref name=Sheehan/>{{Rp|}} Their weapons were principally of Chinese<ref>[https://web.archive.org/web/20150213214134/http://www.militaryhistoryonline.com/20thcentury/articles/chinesesupport.aspx Chinese Support for North Vietnam during the Vietnam War: The Decisive Edge], Bob Seals, Military History Online, 23 September 2008</ref> or Soviet manufacture.<ref>Albert Parray, ''Military Review'', [http://calldp.leavenworth.army.mil/eng_mr/txts/VOL47/00000006/art2.pdf "Soviet aid to Vietnam"] {{Webarchive|url=https://web.archive.org/web/20110428210157/http://calldp.leavenworth.army.mil/eng_mr/txts/VOL47/00000006/art2.pdf |date=28 April 2011}}, June 1967</ref> In the period up to the conventional phase in 1970, the Viet Cong and PAVN were primarily limited to 81&nbsp;mm mortars, recoilless rifles, and small arms and had significantly lighter equipment and firepower in comparison with the US arsenal. They relied on ambushes, superior stealth, planning, marksmanship, and small-unit tactics to face the disproportionate US technological advantage.<ref>{{Cite book |last1=Miller |first1=Robert |title=Indochina and Vietnam: The Thirty-five Year War, 1940–1975 |last2=Wainstock |first2=Dennis D. |publisher=Enigma Books |year=2013 |isbn=978-1-936274-66-6 |pages=[{{GBurl|id=jexmAgAAQBAJ|pg=PT101}} 101]–102 |language=en}}</ref>

After the Tet Offensive, many PAVN units incorporated [[light tank]]s such as the [[Type 62]], [[Type 59 tank]]., [[BTR-60]], [[D-74 122 mm field gun|Type 60 artillery]], [[Amphibious vehicle|amphibious tanks]] (such as the [[PT-76]]) and integrated into new war doctrines as a mobile combined-arms force.<ref name=":9" /> The PAVN started receiving experimental Soviet weapons against ARVN forces, including [[Man-portable air-defense system|MANPADS]] [[9K32 Strela-2]] and [[anti-tank missile]]s, [[9M14 Malyutka]]. By 1975, they had fully transformed from the strategy of mobile light-infantry and using the people's war concept used against the United States.<ref name=":9">{{Cite web |date=12 June 2006 |title=North Vietnam's Master Plan {{!}} HistoryNet |url=http://www.historynet.com/north-vietnams-master-plan.htm |access-date=1 June 2018 |website=www.historynet.com |language=en-US|archiveurl=https://web.archive.org/web/20230409052605/https://www.historynet.com/north-vietnams-master-plan/?f|archive-date= April 9, 2023}}</ref>

The US service rifle was initially the [[M14 rifle|M14]]. The M14 was a powerful, accurate rifle, but it was heavy, hard-recoiling, and especially unwieldy in jungle fighting, as it was unsuited for the combat conditions, often suffering from feed failure. It was gradually replaced by the [[M16 rifle]], designed by [[Eugene Stoner]], between 1964 and 1970. When first deployed, the M16 also suffered from a propensity to jam in combat, leaving the soldier defenseless and potentially killing him.<ref>{{Cite news |last=C.H. Chivers |date=2 November 2009 |title=How Reliable is the M16 Rifle? |work=[[The New York Times]] |url=http://atwar.blogs.nytimes.com/2009/11/02/how-reliable-is-the-m-16-rifle/|archiveurl=https://web.archive.org/web/20230409001432/https://archive.nytimes.com/atwar.blogs.nytimes.com/2009/11/02/how-reliable-is-the-m-16-rifle/|archive-date=April 9, 2023}}</ref> According to a congressional report, the jamming was not related to operator error or to an inherent flaw in the rifle, but instead due to a change in the gunpowder to be used in the rifle's cartridges, which led to rapid powder fouling of the action and failures to extract or feed cartridges. This decision, made after "inadequate testing", proved that "the safety of soldiers was a secondary consideration."<ref>{{Cite book |last=Maraniss |first=David |url=https://archive.org/details/theymarchedintos00mara |title=They Marched into Sunlight: War and Peace Vietnam and America October 1967 |publisher=Simon and Schuster |year=2003 |isbn=978-0-7432-6255-2 |page=[https://archive.org/details/theymarchedintos00mara/page/410 410] |url-access=registration}}</ref> The issue was solved in early 1968 with the issuance of the M16A1, featuring a chrome-plated bore, which reduced fouling, and the introduction of a cleaner-burning powder.<ref name=Hastings/>{{Rp|408–411}} Incorporating features from the German [[FG-42]] and [[MG-42]], the U.S. replaced their earlier [[M1919 Browning]] in most roles with the [[M60 machine gun]], including on helicopters where it was used for [[suppressive fire]]. While its issues were not as severe as they were in the M14 or M16, the M60 still could fail to fire at crucial times – spent casings could get stuck inside of the chamber, meaning the barrel would have to be replaced before it could fire again.<ref>{{Cite book |last=Dockery |first=Kevin |title=The M60 Machine Gun |date=2012 |publisher=Osprey Publishing |page=58}}</ref>
[[File:UH-1D helicopters in Vietnam 1966.jpg|thumb|[[Bell UH-1 Iroquois|UH-1D]] helicopters airlift members of a U.S. infantry regiment, 1966]]

The [[Lockheed AC-130|AC-130 "Spectre"]] Gunship and the [[UH-1]] "Huey" gunship were used frequently by the U.S. during the war. The AC-130 was a heavily armed [[attack aircraft|ground-attack aircraft]] variant of the [[Lockheed C-130 Hercules|C-130 Hercules]] transport plane, while the Huey is a military helicopter powered by a single, [[turboshaft]] engine; approximately 7,000 UH-1 aircraft saw service in Vietnam. The U.S. heavily armored, 90&nbsp;mm [[M48 Patton|M48A3 Patton tank]] saw extensive action during the Vietnam War, and over 600 were deployed with U.S. Forces. US ground forces also had access to B-52 and F-4 Phantom II and other aircraft to launch [[napalm]], [[White phosphorus munitions|white phosphorus]], [[tear gas]], [[chemical weapon]]s, [[precision-guided munition]] and [[cluster bomb]]s.<ref>{{Cite news |last=Biggs |first=David |date=25 November 2017 |title=Opinion {{!}} Vietnam: The Chemical War |language=en |work=The New York Times |url=https://www.nytimes.com/2017/11/24/opinion/vietnam-the-chemical-war.html?mtrref=www.google.ca&assetType=opinion |access-date=20 June 2018|archiveurl=https://web.archive.org/web/20230416211026/https://www.nytimes.com/2017/11/24/opinion/vietnam-the-chemical-war.html?mtrref=www.google.ca&assetType=opinion|archive-date=April 16, 2023}}</ref>

===Radio communications===
[[File:North Vietnamese SA-2.jpg|thumb|North Vietnamese SAM crew in front of SA-2 launcher. The Soviet Union provided North Vietnam with considerable anti-air defense around installations.]]

The Vietnam War was the first conflict where U.S. forces had [[secure voice]] communication equipment available at the tactical level. The National Security Agency ran a crash program to provide U.S. forces with a family of security equipment, codenamed [[NESTOR (encryption)|NESTOR]], fielding 17,000 units initially; eventually 30,000 units were produced. However, limitations of the units, including poor voice quality, reduced range, annoying time delays and logistical support issues, led to only one unit in ten being used.<ref name="NSA">{{Cite web |year=1981 |title=A History of U.S. Communications Security; the David G. Boak Lectures |url=https://www.governmentattic.org/18docs/Hist_US_COMSEC_Boak_NSA_1973u.pdf |publisher=National Security Agency |page=43 |volume=2|archiveurl=https://web.archive.org/web/20230326032806/https://www.governmentattic.org/18docs/Hist_US_COMSEC_Boak_NSA_1973u.pdf|archive-date=March 26, 2023}}</ref> While many in the U.S. military believed that the Viet Cong and PAVN would not be able to exploit insecure communications, interrogation of captured communication intelligence units showed they could understand the jargon and codes used in real time and were often able to warn their side of impending U.S. actions.<ref name=NSA/>{{Rp|4,10}}

===Extent of U.S. bombings===
{{See also|Operation Rolling Thunder|Operation Menu|Operation Freedom Deal|CIA activities in Laos}}
The U.S. dropped over 7&nbsp;million tons of bombs on Indochina during the war, more than triple the 2.1&nbsp;million tons of bombs the U.S. dropped on Europe and Asia during all of [[World War II]] and more than ten times the amount dropped by the U.S. during the Korean War. 500 thousand tons were dropped on Cambodia, 1&nbsp;million tons were dropped on North Vietnam, and 4&nbsp;million tons were dropped on South Vietnam. On a per capita basis, the 2&nbsp;million tons dropped on Laos make it the most heavily bombed country in history; ''The New York Times'' noted this was "nearly a ton for every person in Laos."<ref name=KiernanTaylor/> Due to the particularly heavy impact of cluster bombs during this war, Laos was a strong advocate of the [[Convention on Cluster Munitions]] to ban the weapons, and was host to the First Meeting of States Parties to the convention in November 2010.<ref>{{Cite web |date=November 2011 |title=Disarmament |url=http://www.unog.ch/80256EE600585943/(httpPages)/B3F3E37A2838630FC125772E0050F4F7?OpenDocument |access-date=20 September 2013 |website=The United Nations Office at Geneva |publisher=United Nations}}</ref>

Former U.S. Air Force official Earl Tilford has recounted "repeated bombing runs of a lake in central Cambodia. The B-52s literally dropped their payloads in the lake." The Air Force ran many missions of this kind to secure additional funding during budget negotiations, so the tonnage expended does not directly correlate with the resulting damage.<ref>{{Cite web |last=Greenberg |first=Jon |date=11 September 2014 |title=Kissinger: Drones have killed more civilians than the bombing of Cambodia in the Vietnam War |url=http://www.politifact.com/punditfact/statements/2014/sep/11/henry-kissinger/kissinger-drones-have-killed-more-civilians-bombin/ |access-date=18 September 2016 |website=[[Politifact.com]]}}</ref>