Was Trump justified to try to buy the rights to a COVID-19 vaccine?

Trump has no responsibility to the rest of the world

Question: Was Trump justified to try to buy the rights to a COVID-19 vaccine?
Position‹3 of 4›: World leaders are only responsible for their own citizens
Argument‹3 of 3: Trump has no responsibility to the rest of the world

In an ideal world perhaps we'd all do the best for everyone else. Unfortunately, that isn't how politics works, nor world leaders operate. The President's only loyalty is to his citizens, and making sure they're protected is his only job.

The argument

A government's job is ultimately to protect its own citizens, and President Trump's attempt to purchase the COVID-19 vaccine is a reflection of such a duty. Assisting all citizens of the world should always be an aspiration, however, it may be too idealistic. Instead, it is simply far more feasible for world leaders to pursue what is in their own countries best interest. This is especially true within the United States when considering the fourteenth amendment. In other words, the fourteenth amendment states that all born in the U.S.A have not only rights to citizenship but a right to protection, life, liberty, or property. Thus, Trump's actions were in accordance with the constitution.

Premises

[P1]A government's fundamental job is to protect its own citizens, and assisting all the world's citizens, while an aspiration, is too idealistic to be feasible. [P2] In the US the Fourteenth Amendment guarantees those born in the country a right to protection of life, liberty and property, so Trump's attempt to secure the vaccine for Americans accorded with that constitutional duty. [C] Therefore Trump had no responsibility to the rest of the world, because world leaders are responsible only for their own citizens.

Counter-arguments

As an international leader, Trump certainly does have a responsibility to all citizens of the world. Nationalities are simply titles, we are all part of a bigger human collective. And due to such a reality. we should have each other's best interests in mind. It is through this understanding that peace and harmony between countries can be established. In other words, as the leader of one of the most powerful countries in the World, President Trump should promote and protect all human rights, not just human rights as they pertain to America, and not just when it is convenient. Trump should actively protect these rights throughout his presidency. What is the point of even proclaiming human rights if no world leader will follow them or call out their peers for failing to?

Rejecting the premises

[Rejecting P1] That a government's primary duty runs to its own citizens is widely accepted and does not establish the stronger claim of no responsibility to anyone else; the premise moves from a priority to an exclusion without argument. [Rejecting P2] The Fourteenth Amendment constrains how government treats persons within its jurisdiction; it does not authorise any particular foreign purchase, so citing it shows at most that the action was not prohibited — while the position needs it to have been required.