Of course. They have a responsibility to ensure that you will be a good employee. Doing a little investigating, they discovered that you weren't honest about your employment history.
I'm sure that raised a red flag and they contacted your former employer to find out. Not only can they do that, they have a responsibility to do exactly that.
Sure, why couldn't they. They have as much freedom as you do. They can talk to whomever they please and they can tell anyone anything they know about you as long as it is true.
Your not placing it on a resume makes no difference. That means your former employees records on you, including almost all information belongs to the employer. He can sell it to spammers, put it on a bill board in the middle of town, or tell someone doing a background check on you.
The only exception is certain financial information such as bank account information and SSN.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.