Volodymyr Zelenskiy met US senators while in Washington, where Ukraine's successes have played well. (AP PHOTO)Volodymyr Zelenskiy met US senators while in Washington, where Ukraine's successes have played well. Ukraine's almost daily long-range drone and missile strikes using domestically developed weapons have battered Russian oil facilities for months. The refineries have a combined annual production capacity of around 30 million tonnes of oil, according to Ukraine, and make a vital contribution to Russia's military effort and its government revenue. That stance had raised the spectre of Ukraine and Europe having to stand up to Russian aggression alone.