"Assuming oneself or one's country to be an instrument of God's will is a dangerous path to go down."
Quite so!   The key is to be an instrument and not confuse my will with God's.  God's will is that we love one another as God loves us.  That is a lot to handle.  What the" loving thing" is in any given situation is not always easy to discern.  I do believe we create the world we live in by the attitudes we have and the actions we take and we have pretty well made a mess of things.  Christ is the example we should, in my opinion, seek to follow and that does mean taking up the cross of love every day and doing the best we can to better life for everyone.  I need, as a Christian, to see Christ in every other human being and, more importantly, strive to be Christ for others.  Big order!