<P> Two aircraft which were prominent in the war were the AC - 130 "Spectre" Gunship and the UH - 1 "Huey" gunship . The AC - 130 was a heavily armed ground - attack aircraft variant of the C - 130 Hercules transport plane; it was used to provide close air support, air interdiction and force protection . The AC - 130H "Spectre" was armed with two 20 mm M61 Vulcan cannons, one Bofors 40mm autocannon, and one 105 mm M102 howitzer . The Huey is a military helicopter powered by a single, turboshaft engine, with a two - bladed main rotor and tail rotor . Approximately 7,000 UH - 1 aircraft saw service in Vietnam . </P> <P> The Claymore M18A1, an anti-personnel mine, was widely used during the war . Unlike a conventional land mine, the Claymore is command - detonated and directional, meaning it is fired by remote - control and shoots a pattern of 700 one - eighth - inch steel balls into the kill zone like a shotgun . </P> <P> The aircraft ordnance used during the war included precision - guided munition, cluster bombs, and napalm, a thickening / gelling agent generally mixed with petroleum or a similar fuel for use in an incendiary device, initially against buildings and later primarily as an anti-personnel weapon that sticks to skin and can burn down to the bone . </P> <P> 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 code named 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 . While many in the U.S. military believed that the Viet Cong and NVA would not be able to exploit insecure communications, interrogation of captured communication intelligence units showed they were able to understand the jargon and codes used in realtime and were often able to warn their side of impending U.S. actions . </P>

Who was the united states allied with during the vietnam war