Basically, my argument is that compulsory patriotism is not patriotism. If people want to pledge something on their own because they feel the need, then so be it. But when you require that the pledge be recited through peer pressure, you've invalidated any sort of free exercise and freedom of conscious.
David Waters at the On Faith blog argues this compelling reason why the Pledge is wrong and should be updated.
Second, the greatest threat to American freedom is no longer godless communism but "godly" terrorism -- people who pledge their allegiance to God. Docherty noted that even Stalin's Soviet Union could claim to be "one nation, indivisible, with liberty and justice for all." Today, even a Taliban-led Afghanistan could claim to be "one nation, under God."
Both the constitutions of Iraq and Afghanistan have established the Koran as the basis for its laws, unlike the United States that has a prohibition against church and state conflation in the First Amendment and Article VI for religious oaths. Furthermore, the United States constitution does not establish the Bible as a basis for our laws.
And Waters is correct.
The United States should be a country that is exceptional in its church and state separation since we were the first country to be founded as such.
If we didn't want to be like the Communists in the 50's, then we shouldn't want to be like the highly divided countries of Afghanistan and Iraq (where religious and sectarian violence makes all the headlines) today.