Bear in mind that most places that Americans fought in Europe were at least nominally friendly to the U.S. - France, Belgium, the Netherlands. Hell, I bet even Italian women would have been happy for some lipstick.
The survival kit contents check is from Dr Strangelove, when USSR was the enemy.
But still, just how well disposed to you will the fine ladies of the city you have just bombed?
Depends if the bombing has driven out the Germans.
Plus, civilians don’t survive a war by holding grudges, they do it by getting what they can. If someone offers them something, they take it.
Also, a much higher chance of getting a broken bone from a bad landing but still needing to move while separated from the medic.
Apparently the US has been moving away from morphine injection to a fenatyl ‘lollipop’ for field medics: Injured US Marines to get 'lollipop' instead of morphine
Broken bones is the one injury that medics regularly use morphine for - there’s generally nothing you can do until they get to a hospital, so you might as well make getting there less painful.
Ever so slightly more disposed once I offer them hundreds of dollars in rubles, gold, and ladies’ accessories than they would have been if I could only offer them a combat knife and a survival rifle? 
Historically, the kits would be customized to a degree based on what areas the planes would be flying over. Depending on their planned routes, they might have “blood chits” or phrase guides in languages such as Chinese, Japanese, Korean, Persian, Arabic, etc.
Plus, for a fight against the USSR, they’d logically also try to have ways to appeal to various non-Russian satellite states that might be relatively friendly to westerners to varying degrees, such as Poles or Germans. Plus plus, who knows if the random Russians you run into in the middle of the Eurasian outback would give a hoot about the Soviet government? I honestly don’t know what the popular opinion was throughout Russia during the Cold War, but it’s still better to offer a carrot than nothing.
Dr. Strangelove was a comedy.
Also IIRC the bombers were flying over the Artic so the only between us and the USSR was Canada.
Sent from my SM-G930P using Tapatalk
A black comedy indeed. The kit is explained as a parody referencing many items that many soldiers in WWII found very useful to bribe people, but most importantly for the sexual undertones of the movie (Mistresses, the ratio of females to men in the underground shelters proposed by Dr. Strangelove, the lovely music while planes couple in the opening credits, etc) such a kit assumes a chaotic economy and a loss of a power base as a result of the war in Russia; so, better chances to bribe people or to expect Russian women to offer themselves with little bribes to the Americans if they had become the winners just as it happened to many allied troops in Europe and other parts of the world that suffered a lot of shortages during the war.
Of course the irony and humor of the scene is expected to come to the viewers by realizing later that the coming war was not going to be like WWII, and most if not all those items would be useless when everything is obliterated, at least in WWII many people would survive that then could be convinced or bribed to go along with the conquerors.
Trivia note: Lip-reading you can see that Slim Pickens originally said ‘Dallas’, not ‘Vegas.’
You can get far more with a kind word and a gun than you can with just a gun. 
A good friend just returned from an overseas deployment. He did have an extensive medical kit, including fentanyl. His deployment was to a VERY remote location, with no access to medical care, so they sent him with everything they could.
I’m actually shocked the military uses Fentynal instead of morphine or something line demoral. Fentynal is generally only given to opiod tolerant individuals as the risk of a fatal overdose is quite high in non-tolerant people. It must be a tiny amount of Fentynal.