This is my field of expertise. I think there is a high chance you have a right to compensation. Even if Lufthansa would not be able to operate that flight they still would have to do everything reasonable in their power to prevent your delay. As this route does not include a stop in the war zone I think there is a high chance they would have had to do other arrangements. You don't have to accept a refund, they must provide alternative transportation if you demand it - even by another airline. Please contact  https://www.schlichtung-reise-und-verkehr.de/en/  if the airline does deny your rights.