How many Americans are aware that some, let alone an actual majority, of the Supreme Court's justices believe that this country should be ruled by something other than the Constitution of the United States, laws made pursuant thereto and treaties clearly consistent with it? Assuredly, few of us know that such an assault on our sovereignty is afoot; in all likelihood, fewer still would support it.

The same would likely apply to Harold Koh's embrace of myriad other controversial transnationalist initiatives. He favors U.S. submission to the International Criminal Court, enabling that tribunal to have the right tomorrow to take up the sort of foreign prosecutions of Americans contemplated by Spain's Judge Garzon today.

Dean Koh goes even further than John Kerry, who argued that American uses of force must meet what the Senator euphemistically called a "global test." Koh believes the United States must obtain pre-authorization by the UN Security Council. In keeping with this view, he condemned the U.S. invasion of Iraq, which lacked such a mandate, as "illegal."

The State Department Legal Advisor-designate has also actively opposed virtually every instrument the previous administration deemed necessary to wage and win the war against terror-wielding adversaries. Koh insisted that Guantanamo Bay be closed coercive interrogation techniques be halted and trials in civilian U.S. courts be afforded to captured enemy combatants. To be sure, these positions largely track with those of President Obama, although the latter has left himself some latitude in their implementation. Koh's critique of the government's terrorist surveillance, though, is even more extreme than that of Mr. Obama, who as a Senator voted to allow the program to continue.

Not surprisingly, Mr. Koh seems untroubled by international accords that assault our Constitution-based sovereignty. These include such onerous and invasive agreements as the Law of the Sea Treaty, the Convention on the Elimination of All Forms of Discrimination Against Women and the Convention on the Rights of the Child. Another candidate could be the Organization of the Islamic Conference's effort to circumscribe freedom of expression by criminalizing speech that "offends" Islam.

It is absolutely predictable that the United States will find itself under ever greater assault in the form of lawfare as notions of the supremacy of transnational law take hold among elites, both here (notably, in the Supreme Court) and abroad. Mr. Obama can spare himself and the country considerable grief when he meets this week in Europe and Turkey with some of the leading practitioners of lawfare by repudiating Judge Garzon's extraterritorial over-reach, rejecting the application of transnational law more generally and selecting a State Department Legal Advisor who is an avowed "nationalist," not a committed "transnationalist."