British and American military officials said that as Russia’s offensive in Ukraine has faced setbacks, Russian forces have ramped up the use of rocket attacks and other long-range fires, increasingly striking civilian infrastructure, leading to more civilian casualties. British Defense Secretary Ben Wallace told the BBC on Tuesday that Russian forces were becoming frustrated by the lack of progress in parts of Ukraine and were increasingly resorting to what he described as brutal tactics. Wallace told the “BBC Breakfast” program that Russian forces were “getting more desperate” and “we are seeing the Russians just double down on brutality.” Russian troops have made significant advances in southern Ukraine but stalled in some other areas. The British defense chief said Russian troops are behind schedule in their offensive, in particular in the north, near the capital Kyiv, where a miles-long convoy has made little progress after its initial thunder run in the early …