Commentary Russian President Vladimir Putin, in an emotional speech on the 21st of this month, made it clear that he believes Ukraine is a part of Russia. U.S. President Joe Biden must now demand that Moscow withdraw its forces from all Ukrainian territory, including Crimea and Donbas. The Kremlin has, among other things, violated the assurances it gave Kyiv in the Budapest Memorandum. Biden, however, has so far shown little inclination to hold Russia to its promises. In December 1994, the United States, Great Britain, Russia, and Ukraine signed the Memorandum on Security Assurances in Connection with Ukraine’s Accession to the Treaty on the Non-Proliferation of Nuclear Weapons, more commonly known as the Budapest Memorandum. In that document, the three parties made six commitments to Ukraine. In the most important of the pledges, they stated that they “reaffirm their commitment to Ukraine, in accordance with the principles of the CSCE Final Act, to …