What qualities displayed by the ancient Greek citizens in the wars with the Persians

What qualities displayed by the ancient Greek citizens in the wars with the Persians are necessary for modern citizens and why?

I believe that the Greeks showed courage and patriotism in the war with the Persians, and it is these qualities, coupled with a love of personal freedom, that modern society needs, because the Greeks were able to overcome disunity, rise above the interests of their policies and look at the situation in the world more broadly. This is how it is worth looking at the modern world, you need not to isolate yourself, but to integrate with the world, but to resist the aggressors, not to let your world order break down. This is what is important. If people in all countries love their countries, be courageous and sincere and sincerely love freedom and humanistic ideals, then the world will become a better and safer place for everyone. And courage will give strength to resist aggressive countries or groups.