Kiev is at a disadvantage in its defence against Russian forces due to restrictions on using US weapons against targets on Russian soil, according to the Washington-based Institute for the Study of War (ISW). The latest report from the US think tank, released on Friday in the US capital, states that Russia exploits these restrictions by launching attacks from protected areas near the Ukrainian border. Ukrainian President Volodymyr Zelensky has called for permission to use US weapons on Russian territory, which is currently denied by the United States to avoid escalation. The US approach to dat…