“入侵者”用英语怎么说？

入侵者最终被赶回到自己的国境内.The invaders were pushed back beyond their own country eventually.我们不能向入侵者屈服.We can never bow the neck to any invaders of our country.坚固的堡垒使入侵者无法攻入.The strong fortress mocked the invaders....