That's not easy to answer because it depends on the version that you're running and the detailed circumstances. But, in general terms, the reason you have not yet reached the same level as other countries is because either
a) the triggers for the GPW have not been achieved. For example, if you have not been attacked yet then you won't get it.
b) the random element may not have come up yet. IIRC, the 1.3a version has a chance of 10% every 10 days once the conditions are satisfied. This could take a while if you are unlucky - an average of 100 days
c) you may be experiencing a bug - there have been problems with every version of this to date.
If you want to avoid these problems then try the 38 campaign in 1.3a. The GPW does not happen in this case and the SU has the same GDE as other countries from the outset. Other factors have been used to balance the game in this case and this has been done specifically to support MP play, for which the 38 campaign is most suitable.
Andrew