Why? Look at the Israelites, he parted the seas, let them cross, while he blocked the Egyptians from attacking with pillars of fire, and when they were across, the Egyptians pursued them and he brought the walls of water down on them.
Now think of it in another sense, think about it, he set our nation in the midst of two oceans, which has protected us from complete and devastating wars. In WW II, other than Pearl Harbor, and while the rest of the world suffered from the destruction of war, the United States was untouched.
God has blessed this nation in ways that we don’t always recognize.
And even in recent times, after the attacks of 9/11, our nation is still protected by God’s invisible hand. A force that we cannot see, but he is ever present in the protection of his people.