No, this article is not about the United States. The Bible verses where this phrase comes from are speaking of Israel.
Deuteronomy 4:5-8 (KJV)
Behold, I have taught you statutes and judgments, even as the LORD my God commanded me, that ye should do so in the land whither ye go to possess it.
Keep therefore and do them; for this is your wisdom and your understanding in the sight of the nations, which shall hear all these statutes, and say, Surely this great nation is a wise and understanding people.
For what nation is there so great, who hath God so nigh unto them, as the LORD our God is in all things that we call upon him for?
And what nation is there so great, that hath statutes and judgments so righteous as all this law, which I set before you this day?
Moses was speaking to the Israelites just before they crossed into the Promised Land. In verse 5 he related that he had taught the people statutes and judgments that God had commanded him to teach. These statutes and judgments were to be how the people were to live when they entered into their land.
The reason for their obedience to these commandments was that they represented wisdom and understanding that would be observable to the nations around them (verse 6). When the nations saw and heard the Jews living out God's commandments they would believe that Israel was a great nation with wise and understanding people.
For what other nation has God so close to them that He answers them and that has righeous statutes and judgments such as those that are in the Torah (the Hebrew word for law) (verses 7 and 8)?
God intended for Israel to be a light to those nations around them. The means of being a light was through Torah living. Israel, when in obediece to the Torah, is a great nation. This concept is found also in Isaiah.
Isaiah 2:2-3 (KJV)
And it shall come to pass in the last days, that the mountain of the LORD'S house shall be established in the top of the mountains, and shall be exalted above the hills; and all nations shall flow unto it.
And many people shall go and say, Come ye, and let us go up to the mountain of the LORD, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the LORD from Jerusalem.
This passage is speaking of a future time, when many people and nations will seek to go to Jerusalem where God will teach them His ways so that they can walk in His paths. For the Torah shall go forth from Jerusalem.
Yet, is spite of God's own words as spoken by Moses and Isaiah, Christianity has decided that observing the law of God is no longer applicable (unless narrowly defined as the Ten Commandments or as New Testament commands). How can we ever hope to be a great people? How can we ever hope to be the light God intended?
1 John 5:2-3 (KJV)
By this we know that we love the children of God, when we love God, and keep his commandments.
For this is the love of God, that we keep his commandments: and his commandments are not grievous.
John 14:15, 21 (KJV)
If ye love me, keep my commandments.
He that hath my commandments, and keepeth them, he it is that loveth me: and he that loveth me shall be loved of my Father, and I will love him, and will manifest myself to him.
If we remember that when John wrote his gospel and epistle there was no New Testament, it becomes obvious that John was speaking about the Torah.
Torah living is how Christianity can be great and be a light to others.