1. For reasons of practicality and cost, nations should in many cases devote more resources to their own citizens than to foreigners.The moral is that all individuals count equally, but individuals will be best off if governments focus on serving their own citizens. This is a general rule and should be broken for things like Boxing Day tsunamis, in other words governments should still take foreigners into account, but less so than citizens.
2. Once the costs mentioned in #1 are taken into account, foreigners are still "worth less" than citizens.
#2 does not follow from #1, that is a mistake in moral arithmetic. #2 is false.
Samuel Brittan talks of a weighing sytem assigning more value to citizens than foreigners in the same way that parents do for their children, it's ok to save your kid instead of 5 other kids maybe, but surely not 100 000.
This is all fine, but if governments start thinking this has some deeper significance rather than just a useful rule of thumb then they will seriously underestimate the costs of war.
When you venture past your borders, all lives count equally as well as property etc. Can citizens and governments be trusted to mean it when they pat lip service to these ideals?