I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God. WWG1WGA
(b) Who May Administer.—
The oath may be taken before the President, the Vice-President, the Secretary of Defense, any commissioned officer, or any other person designated under regulations prescribed by the Secretary of Defense.
https://www.law.cornell.edu/uscode/text/10/502
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