The British fought in Korea, not Vietnam.
See response below.
All out war, minus nukes and invasion of the north.
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"we can/will bomb them back to the stone age"
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The Vietnam War was the last major war fought by the Centurion medium tank under British or Australian colors (flags).
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Shortly after the Americans were kicked out of Vietnam, the British won the Falklands War.
Australia and New Zealand did, but the UK did not.
The Iraq War and the Vietnam War, in terms of military engagements, combat-style, and overall missions have nothing at all in common either than the fact that they both take place on the continent of Asia. However, the domestic response to both wars is comparable in that there was much domestic fatigue. However, as the draft affected a large swath of America, the domestic response to Vietnam was far sharper and more prevalent than the response to Iraq.
I believe the slogan at the time was, "All the way with LBJ". That probably says it all.