Based solely on the information gathered, he could already assert that allowing Charlemagne Army... no, it should be said that any country's military launching an attack on the defenses before them, regardless of their motives, such an act could be deemed as murder.
Overall, the elves were diligent and hardworking warriors. Given sufficient civil engineering equipment and materials, they had constructed a defensive zone far more practical and robust than the Maginot Line in a very short time.