How a closer Commonwealth might divide Vietnam-era duties

Would Australia and New Zealand participate in Vietnam if they belonged to a more closely united Commonwealth?

Their participation would still depend on their interests and on how the union worked; the discussion also considers allies dividing responsibilities between theaters.

The scenario asks about Australia and New Zealand within a much closer Commonwealth union. Their involvement in Vietnam would still depend on their interests and the circumstances of the war. The discussion notes that domino theory was shared beyond the United States. Britain's North Atlantic responsibilities are offered as an example of allies dividing commitments between theaters.