Guaranteeing Ukrainian Autonomy by Reinforcing its Defense (GUARD) Act of 2021 This bill provides support for Ukraine and imposes sanctions related to Nord Stream 2, the pipeline constructed to increase exports of natural gas from Russia. If Russia or any of its proxies militarily advance into Ukraine's territory or airspace beyond the area occupied as of December 15, 2021, the Department of State must designate Russia a state sponsor of terrorism. The bill authorizes the State Department to provide Foreign Military Financing assistance to Ukraine in FY2022. The bill also authorizes providing Ukraine with lethal assistance, such as anti-armor weapon systems and anti-aircraft weapons systems. From FY2022-FY2026, Ukraine shall have priority access to excess defense articles. During the same time period, the bill also authorizes providing Ukraine with assistance, including (1) International Military Education and Training assistance; (2) assistance to strengthen cybersecurity and intellectual property enforcement; (3) support and training for banking reform, subsidy reform, corporate governance, and the privatization of state-owned enterprises; and (4) assistance to combat corruption and improve the rule of law. Within 15 days of this bill's enactment, the President must impose sanctions on any entity responsible for planning, constructing, or operating Nord Stream 2, as well as any corporate officer of such an entity. The bill also subjects the President's authority to waive certain sanctions to congressional review. The bill requires reports to Congress on various topics, including a strategy on using U.S. diplomacy to support Ukraine.