Answer:
No, it is not ethical to use inhumane tactics, regardless of whether the enemy has used them. The use of inhumane tactics is a violation of international law and basic human rights. The fact that the Japanese used kamikazes and surprise attacks does not justify or excuse the United States or any other country to engage in similar actions.
Rather than stooping to the level of the enemy, it is important for the United States to uphold its own values and ethics, and to find ways to win the war through more humane means. Ultimately, using inhumane tactics only serves to perpetuate a cycle of violence and hatred, and can lead to further conflicts in the future.