Answer: "Permitted no such distinction" means that no differentiation or distinction was allowed. It implies that a certain rule, policy, or decision did not allow for exceptions or different classifications, and everything was treated equally. The phrase suggests a strict adherence to a set standard with no room for deviation.
Explanation: In this context, "permitted no such distinction" means that the May 12 document was more strict and did not allow for any exceptions or differentiations in regards to American participation in the European war. The original draft allowed for Japan's Axis obligation to come into force only if the United States aggressively attacked Germany, but the May 12 draft did not have this differentiation and did not allow for any distinction between aggressive attack and other forms of assistance. This stricter draft also obliged the United States to refrain from forming an alliance with Britain, and went even further to preclude even aggressive measures of assistance, such as Lend-Lease.