Stripping the citizenship of those who take up arms against the United States is not a controversial proposition. Indeed, under existing law, American citizenship can be taken away from any adult who, among other actions, makes a formal declaration of allegiance to a foreign state, serves in the armed forces of a foreign state if such armed forces are engaged in hostilities against the United States, or commits any act of treason against the United States. The Lieberman-Brown bill, which adds to that list the provision of material support to State Department-recognized terrorist organizations (most notably Al Qaeda) or actively engaging in hostilities against the United States, is thus not problematic on its face. It merely clarifies, in an age where America’s enemies aren’t necessarily other countries, that a person need not ally himself with a hostile “foreign state” to risk expatriation.

Still, the Terrorist Expatriation Act does raise concerns about how the new citizenship-stripping provisions would be applied. Expatriation is a serious remedy that is warranted only in the most serious cases — such as, indeed, treason or taking up arms against your own country. If and when the act becomes law, courts will maintain a high bar for what constitutes “material support” of terrorist organizations (such that it constitutes relinquishing U.S. nationality), and the subject of the expatriation action will — under existing law that will remain unchanged — have notice and opportunity to challenge the decision.

In short, this is neither a radical threat to civil liberties nor an ineffectual political stunt. Assuming the above constitutional protections remain in place, the expansion of federal expatriation law should be seen as a prudent, necessary, and uncontroversial measure that deals with the realities of the modern world.