So, yes, putting a fortification around Bagram in Afghanistan or a base in Syria fits precisely within the scope of the statute. The bases are classic military installations in active war zones (thus, obviously requiring the use of the armed forces) and in a declared emergency, the president would absolutely have the power to move funds to fortify those installations. But what if there is no war zone? What if there’s no military installation to fortify? Well, here’s Miller to tell us that the statute allows Trump to build a permanent civilian structure (to be permanently manned by civilians) to protect the troops who are present on a temporary deployment in peacetime along the border of an allied nation. That’s absurd.

This interpretation simply doesn’t match the plain language and obvious intent of the relevant statute. The hope for the administration is that the mere invocation of the troops — even in peacetime — induces a court to defer to the president. But judicial deference to presidential national-security determinations has never been unlimited, and in the total absence of a state of armed conflict granting the president the exclusive power to interpret (and torture the meaning of) the relevant statutes would do damage not just to the separation of powers but would also violate basic principles of originalism and textualism.