Art 2, Sec. 3 of the US Constitution obligates the President to investigate and ask for investigations of corruption in countries we provide funds to.
Article 2, Section 3 says no such thing. Here, read it:
Article 2, Section 3
He shall from time to time give to the Congress Information of the State of the Union, and recommend to their Consideration such Measures as he shall judge necessary and expedient; he may, on extraordinary Occasions, convene both Houses, or either of them, and in Case of Disagreement between them, with Respect to the Time of Adjournment, he may adjourn them to such Time as he shall think proper; he shall receive Ambassadors and other public Ministers; he shall take Care that the Laws be faithfully executed, and shall Commission all the Officers of the United States.