Some people believe that there is a "human social contract" or "natural rights" or some variation thereof, but it's incorrect to say that the Constitution enshrines that concept. What the Constitution says is that the rights the colonists already possessed, by virtue of long-standing practice and their status as Englishmen, were not prejudiced by the new Constitution.

It's blatant historical revisionism to assert that a group of people who didn't believe that black people in America had any rights somehow believed in a concept of universal natural rights that we should apply to people in Yemen or Afghanistan.

The Constitution is fundamentally a product of "social contract" thinking. The preamble says:

"We the people of the United States, in order to form a more perfect union, establish justice, insure domestic tranquility, provide for the common defense, promote the general welfare, and secure the blessings of liberty to ourselves and our posterity, do ordain and establish this Constitution for the United States of America."

When you see uses of "the people" in say the First Amendment, it's a clear reference to "the people of the United States" not "people everywhere." It's not necessarily limited to U.S. Citizens, but it is limited to people who have some nexus to the U.S., either through citizenship or presence on American soil.

Yes, "the people" formed the United States. This isn't disputed. The entire body of the Constitution deals with limiting and delineating federal power.

Right. But if you read the Constitution in light of the Federalist papers, it is clear that those limitations on federal power apply domestically. Otherwise, it is clear that the framers intended to create a fully sovereign entity on the international stage, with the sovereign right to do all the things sovereigns have the right to do, which is pretty much everything. Indeed, that was one of the purposes of the Constitution: to create a strong central government that could act in international matters the same as the European sovereigns. The idea of the Constitution recognizing rights of foreigners that limit the power of the federal government internationally runs wholly counter to all that.

I don't understand what you mean by "all the things sovereigns have the right do do, which is pretty much everything." ?

Clearly there are laws, and the US government is bound to those laws. Are you saying that the US government can have people killed? Torture? And as long as the US legal system isn't there to intervene it is legal?