You can be the most inspired thinker of our time, but that's practically worthless if you're unable to express yourself. In fact, an average idea explained effectively - concisely and lucidly - is more persuasive. So, the ideal is to marry a great idea with a great execution. But that takes time to work up to; personally I'm learning to write more incisively since I tend to ramble on. For your first story, I wouldn't worry about having an ingenious plot line. Instead, I'd focus on practicing the micro - sentence structure, rhythm, imagery. If it's a joy to read, people will be willing to engage with your story.
Nevertheless, we can't just discount the big ideas which make up the 'backbone'. Having a strong, centralised theme is especially useful during planning. It underscores the different plot lines, character development and everything down to word choice. Is the core idea about enlistment and war? Is it about revenge and redemption? Knowing what that is will help you realise where the story should be heading. At that point, I would begin writing. During the process, other themes and ideas can be layered on and enhanced naturally.
Your idea is neither interesting or boring. Therefore, it's essential that you pay attention to the details. Hope this helps, good luck!
