Irenaeus said:
Dear Brother Ignatius,
Even the Vatican is not the "City of God,"
That is why I said the Vatican Flag is the flag of the CONSULATE of the Kingdom.
There is nothing wrong with offering allegiance to one's country and flag and I do not mean to imply that it is a problem.
I do intend to imply and state, however, that as Christians our FIRST country is the Kingdom of God and our FIRST allegiance is to God and His Kingdom and as such God' kingdom is a higher priority.
Jesus was referring to this sort of thing when he said, "Give unto Caesar that which is Caesar's".
Thus one can take the pledge to the Vatican Flag AND the pledge to their country's flag without contradiction. But one must always find the Kingdom of God as the First and primary citizenship if we be Christian.
For me and me alone, I tend to fly only the Vatican Flag and not the U.S. Flag. I feel in a really palatable way that this little property belonging to the Legion of St. Michael is like a consulate and territory of God's Kingdom and not of South Dakota. Now don't misunderstand me, I am not like the kooks in the wilderness of Montana who believe they has seceded from the United States and are not subject to its laws. In terms of legally and morally, I am a citizen of the United States and a recipient of the privileges that entails, and appreciate those privileges, and are subject to the laws of this country, and did serve this country in time of war.
For me personally, however, and this applies to me and no one else, I do not feel to be a citizen of any country, but God's country. I literally do not care what geography I may reside upon. Despite the privileges of living in the United States, I have no problems with the idea of living as an ex-patriot in some third world country or even living in an oppressive country. In some ways living in an overtly oppressive society is better then living in a society like the United States that has many oppressions, but hidden behind noble words.
Anyway, while this Allegiance to the Vatican Flag has a particular significance to me, no Catholic should be shy to make the pledge (and remain a patriot to their country at the same time).