No president must request a Declaration of War, it is not his role. Show me where the Constitution requires this. Congress knows what is going on in the world, they deliberate and they pass it and require him to act on it. Congress failed this country.
We'll just have to agree to disagree on this.
The idea of a Congress declaring war on its own without the Constitutionally-defined Commander in Chief asking for such a declarationg is in my mind close to absurd ... but then so was much of the Carter years. :-)