Interesting that this time the seeds of the alliance come from small powers looking for security rather than the combined aims of a super-power and a number of medium sized ones.
A couple of points:
a) Small but funny typo. "and the singing ceremony at Ditchley House in Oxfordshire". Does this TL really need a Eurovision Song Contest?
b) My eyes are definitely getting worse. I was wondering why the alliance badge referred to 1913 then I realised one of the I's was a L!
c) On the Polish caution about getting dragged into "any Colonial conflicts that all of the founding members but themselves might eventually have" where is this Irish colonial empire? . I also notice the implicit view that European territories can't be colonies.
Anyway, good update and insight into the post-war world.