A careful reading of the U.S. Constitution reveals that the majority of the clauses that establish rights actually forbid the U.S. federal government from performing certain actions, period, rather than forbid it from performing those actions or not, conditional on citizenship.

The 4th Amendment protections against unreasonable searches and seizures apply to everyone, everywhere. The U.S. government must always get a warrant, regardless of borders.

U.S. v. Verdugo-Urquidez (1990) [0] established precedent stating otherwise, but I agree with Brennan's dissent and Stevens' concurrence. The majority opinion basically said it would be too difficult for the U.S. to project its power overseas if it still had to obey its own laws there. I don't find political expedience to be an acceptable argument for voiding anyone's rights.

Of course, outside the territorial jurisdiction of the U.S., those protections are unenforceable in practice regardless, because the target likely cannot access any court that might be able to grant relief. It might be interesting for a foreign national to ask to enter the U.S. for the purpose of petitioning for redress of grievances against the U.S. in a U.S. court.

A foreign state need not petition for statehood. It would be sufficient to establish by treaty a court wherein a foreign person may sue a U.S. government and its agents for violations of U.S. law. That would be a double-edged sword, of course. It might also allow a U.S. entity to sue foreign persons for violations of U.S. laws in that foreign state's jurisdiction. (I'm thinking specifically about intellectual property suits.)

[0] https://en.wikipedia.org/wiki/United_States_v._Verdugo-Urqui...

> The 4th Amendment protections against unreasonable searches and seizures apply to everyone, everywhere.

Even granting that, what is "reasonable" depends on a lot of other factors (both legal -- such as specific grants of power to Congress, and laws passed under such grants -- and factual), and the nature of world of multiple sovereign states and the grant of power to Congress to regulate interactions with them, and laws passed by Congress make surveillance of purely foreign material "reasonable" under circumstances where it would not be domestically.

> It would be sufficient to establish by treaty a court wherein a foreign person may sue a U.S. government and its agents for violations of U.S. law. I don't see how such a treaty can be reconciled with Article III; the treaty power does not extend to contravention of the Constitution.

> It might also allow a U.S. entity to sue foreign persons for violations of U.S. laws in that foreign state's jurisdiction.

US entities can already sue foreign persons for violations of US laws in foreign states territory in US courts to the extent that the US law at issue has extra-territorial application.

Being able to actually enforce such a judgment would either require a treaty or that the defendant or defendant's property enter U.S. territory.

I don't see how Article III would prevent the establishment of a U.S. District Court outside the territory of the U.S. There is no distinction there that makes the U.S. District Court for the Western District of Washington any more or less legal than a theoretical U.S. District Court for Ireland and Great Britain, or U.S. District Court for France.

28 U.S. Code § 1331: The district courts shall have original jurisdiction of all civil actions arising under the Constitution, laws, or treaties of the United States. Article III, Section 2, allows an inferior court to hear a civil case brought by a foreign person against the U.S., with the Supreme Court having appellate jurisdiction.

A treaty cannot establish such a court; it can only require that Congress either establish such a court, or be in breach of the treaty.

> I don't see how Article III would prevent the establishment of a U.S. District Court outside the territory of the U.S.

It wouldn't, it would prevent something other than an Article III court from being established by treaty (and anything established by treaty would not be an Article III court.) Congress can establish, and has established Article III courts outside of the US (notably, the U.S. Court for China.) Not, of course, that such a court would be necessary to allow foreigners to sue US officials for violations of Constitutional rights, since offenses cognizable under US law that occur outside of any established judicial district can already be filed in district courts; see, 28 USC Sec. 1391(b)(1) and (b)(3).

(Aside from reducing inconvenience in the US government policing US citizens when granted an extraterritorial privilege to do so, as was the case with the sui generis US Court for China, the main benefit of a foreign-located US Court would be to provide a US -- from a legal perspective -- venue for parties to sue non-US persons local to the area where the court was located where forum non conveniens is less likely to be invoked as a reason for dismissal.)

> A treaty cannot establish such a court

But, upthread, you suggested that a court for the purpose you had in mind would be established by treaty, which I took issue with precisely because a treaty cannot establish such a court.

That's splitting hairs, in my opinion. There is a distinction possible between "established by treaty" and "established by an Act of Congress pursuant to a treaty", but I didn't think it was necessary to make it upthread.

My main point was that foreign states need not become one of the United States to be protected by certain rights clauses in the U.S. Constitution. The key question is how to make the agents of the U.S. obey U.S. laws when outside of U.S. territorial jurisdiction, and there are many possible answers that do not involve extending U.S. territorial jurisdiction beyond its current bounds.

If there are no district courts outside U.S. territory, suing the U.S. as a foreign person may become prohibitively expensive in relation to the magnitude of the offense. The suit could further be impeded by using immigration laws against the plaintiff, possibly impeding discovery or appearances. Retaining a local attorney would be de facto required rather than optional, and hourly rates might combine with currency exchange rates and national economies to ensure that the price tag is simply too high.

> My main point was that foreign states need not become one of the United States to be protected by certain rights clauses in the U.S. Constitution.

But the courts argument is irrelevant to that. To the extent that the US Constitutional rights (or other rights under US law) extend to foreign nationals in foreign territory, the existence of a US court on their soil is irrelevant to such protection, it has no effect either way. So the whole court thing was a non sequitur.

> If there are no district courts outside U.S. territory, suing the U.S. as a foreign person may become prohibitively expensive in relation to the magnitude of the offense.

That might be a practical concern, but it is irrelevant to the actual legal concern, which is that it is well-established law that many protections of the US Constitution do not, in fact, apply to foreign persons outside of the US in the same way as they apply either to US citizens or to persons within the US (some don't apply at all, and even for those that do, the differences in factual circumstance between US and foreign jurisdiction and the fact that the US government has express granted powers in governing relations with foreign nations changes how they apply), and that, in fact, to be protected by those rights in the same way as would be the case for those within the US, the states they were in would, contrary to your argument, need to become part of the United States.

>The majority opinion basically said it would be too difficult for the U.S. to project its power overseas if it still had to obey its own laws there. I don't find political expedience to be an acceptable argument for voiding anyone's rights.

Are any other nations obligated to follow this principle as well, or just the United States?

>A foreign state need not petition for statehood. It would be sufficient to establish by treaty a court wherein a foreign person may sue a U.S. government and its agents for violations of U.S. law.

Why on Earth would we sign such a treaty?

Philosophy and politics do not always intersect in convenient places. The only law that all nations must currently obey is "might makes right". In taking the position that the U.S. may break its own laws whenever following them would be too inconvenient, the Supreme Court implicitly says that the rule of law is more of a guideline, really.

They apparently have not plumbed the deeper meanings of "wherever you go, there you are".

Why, indeed? The foreign state might desire it so that U.S. agents could not act with such impunity against its subjects, but what would be in it for the U.S.? Like any other treaty, that would be a point for negotiation.