This week President Biden announced a ban on US imports of Russian oil and gas. This policy is part of unprecedented economic sanctions punishing Moscow over its invasion of Ukraine. The ban is partly a response to strong bipartisan pressure from Congress. The US and its allies may be reaching the limits of what they can do to help Ukraine with possible cracks in an alliance to help Ukraine. For instance, Poland is understandably concerned about Russian aggression. Ukrainian President Zelensky aptly described Russia's bombing of a maternity and children's hospital yesterday as an 'atrocity.' The US and its allies have taken a number of steps to help Ukraine, including providing weapons and enacting sanctions and now a ban on the US import on Russian oil. The US and other NATO members have so far provided Ukraine 17,000 anti-tank missiles and 2,000 Stinger anti-aircraft missiles. Since the end of WWII, aspects of military engagement and warfare have changed. The U.S. government, other democracies and NATO members are desperately trying to find a way to effectively support Ukraine against a very unstable super power. As the world watches and waits - there are no easy answers.