U.S. Aid

While watching news broadcasts I noticed an inordinate amount of banners on supplies, trucks and shipments etc., stating"U.S. Aid" in the Tsunami ravaged area. This seemed amazing to me that in the midst of a World disaster somebody had authorised the creation of these and made sure they were prominenetly displayed. Was it necessary for them to be so big? This is not a competition. Still the world just has to be informed and constantly reminded that the Americans are doing their bit, right? At this point, it seems all about who is seen to be doing the most. Everything seems to be a competition for Americans. Why?