@Dran-Black If I am reading the rules correctly the 10 IPPs must be paid immediately and can be shared among any aligned powers. So it needs to be cash.
Just to clarify the US IPP reduction: Jan. 1939 the UK attacks Iran, current US income is 16 IPP. I believe the US’s income would immediately reduce to 8 IPPs and when they role the d12 for mobilization that would be completely unaffected. @GeneralHandGrenade correct me if you think that is wrong or unclear.
I also thought militia could be built anywhere as a minimum of one regardless of point values. At least when I’m looking at the V3 rules.