Immediately and with all available means: the Dutch Red Cross and the field hospital on behalf of the Netherlands Voluntary Legion in WWII.
Medical neutrality is one of the main principles of medical-humanitarian aid, and certainly of Red Cross aid. But how does this work in times of foreign occupation? Is it even possible then, or does it almost automatically lead to collaboration? The Dutch example of 1940-1945 gives some insight into this problem. Abandoning its post would end the aid the Dutch Red Cross (DRC) gave, so it was decided to stay in business. This, however, led to adherence to German orders, given not for humanitarian, but for military-political reasons. Amongst other things, the DRC helped to equip a field hospital for Dutch volunteers to the Waffen-SS on the eastern front, so directly strengthening the German war effort. It was clear that the doctors and nurses of this field hospital would do next to nothing to help save Russian sick or wounded, and that, if necessary, they would have to fight alongside German and Dutch soldiers.