"Everyone has the right to leave any country, including his own, and to return to his country. " [0] UN Universal Declaration of Human Rights, article 13. Supported by the US, but not legal binding.

"1. Everyone lawfully within the territory of a State shall, within that territory, have the right to liberty of movement and freedom to choose his residence.

2. Everyone shall be free to leave any country, including his own.

3. The above-mentioned rights shall not be subject to any restrictions except those which are provided by law, are necessary to protect national security, public order (ordre public), public health or morals or the rights and freedoms of others, and are consistent with the other rights recognized in the present Covenant.

4. No one shall be arbitrarily deprived of the right to enter his own country." International Covenant on Civil and Political Rights, Article 12 [1]. Ratified by US.

[0] http://www.ohchr.org/EN/UDHR/Documents/UDHR_Translations/eng...

[1] http://www.ohchr.org/EN/ProfessionalInterest/Pages/CCPR.aspx

The U.N. charta also decides when a war is legitimate - most if not all recent U.S. wars were not following those simple rules.

Unfortunately, the quoted declarations are simply ignored by some signing countries.

How much weight does our court system give to treaties?

I assume that if Congress explicitly passed a low contradicting a treaty, then our courts would honor Congress's law. However, given that Congress approved the treaty, it seems reasonable that when judging the actions of a federal agency (such as the IRS), the courts would try to interperat the law in a way consistent with our treaties.

Paying—or at least filing—your taxes is the law in the USA. Generally speaking, breaking laws results in you losing some freedoms. I'm sure there are other crimes for which you would lose the right to travel out of the country.

Anyways, the article states that this would only apply in cases where an individual has over $50,000 in unpaid taxes. Statistically speaking, I don't imagine that very many people find themselves in that situation.

I don't know how many people fall in to the category, but some of the millions of American citizens living abroad may. While it is rare to be prosecuted, legally the fines can quickly pile up if while you are living abroad, you forget to report every cent that you own or partially own abroad.

Generally speaking, in order to lose freedoms due to lawbreaking, the government must first prove beyond reasonable doubt that you have in fact violated the law. This does not appear to be the case here.

Technically, you can leave on ID besides a passport if you have another qualifying form of identification for land/sea travel to most North American countries.