Possible Clues:

• Perhaps Californian Guardian is more rigorous
• One from Europe or North America
• Not one of Easter?
• We get more forbidding with no-one from the East
• Native encountered by young man taking Soule's advice
• How we get to be more forbidding away from the East
• You and I want rigorous first entry requirements for European
• Could be European bird diving into river
• Our side harder on Frenchman compared to Thai, say
• American perhaps you and I back expressing reluctance