Lots of tank appropriate acreage in the northern portion of Oz...attack helicopters and tanks work hand in glove on the ground in advance across vast distances...it's modern warfare 101...their very special soviet fighters would gain relatively easy air superiority over our flyboy's and their copters and tanks would advance the line mopping up all bound on the ground humans along the way.
If they do not already, expect a big purchase of ocean going transporters....it's their sovereign right to have this capability.
Hope our army reserve now has guns that don't jam on every 3th bullet fired lol oh and food rations with better than only 1/3 the calories necessary to fight a war.