making enquiries!

I have been motivated to try making enquiries about Polish archives in Ukraine. There is a Pole living near, who speaks both Polish and Ukrainian, his partner says he will be happy to help me, whether Dareck feels the same way I'm not sure, we visited before he had had his lunch and it is not good to keep a man from his food!
He said he would make enquiries at the Polish Embassy as he was to go there on Wednesday.  This has set me thinking and re-looking at the information I have. My father was born in 1912 and the part of Poland where he lived was not in Poland at that time, was he born elsewhere? What makes nationality?  I have been feeling very philosophical and rather resentful. When I knew nothing I was happy just to know that my father was Polish, now I know less and I am not happy about it. The result is that I have: 1) emailed the British Embassy in Kiev and the Ukrainian Embassy in London; and 2) downloaded 4 books on Polish history, to try and resolve my lack of knowledge on the boundaries of the country prior to WWII.
I don't expect to get much help from the Embassies, I expect that all document were destroyed, either during the war or during the 'Cold War'.
The books are:
The Reconstruction of Nations: Poland, Ukraine, Lithuania, Belarus, 1569-1999 by Timothy Snyder
Polish History before 1910 by Robert Nisbert Bain
With Fire and Sword, an historical novel of Poland and Russia by Henryk Sienkiewicz
Pan Michael An historical Novel of Poland, the Ukraine and Turkey by Henryk Sienkiewitz

Two of these are novels but may give me some insight, of the ohers I hold the most hope withTimothy Snyder who starts his book by asking: 'When do nations arise, what brings ethnic cleansing, how can states reconcile?'
If he can start to answer some of those questions to my satisfaction I will be very happy! I will try and reconcile myself to the fact that I will probably never know anymore about my father though I will still go to Septfonds in October.