So the 1964 manga had some pretty glaring racial stereotypes, such as Chang's "3" squinty Asian eyes, and Pyumna's infamous Blackface, which earned the manga some controversy. But remember - the story of Cyborg 009 involves nine cyborgs with different nationalities trying to stop Black Ghost, which seems to be the embodiment of war. Since the manga seems to be anti-war themed, Ishinomori might be trying to teach us that war affects everyone, regardless of nationality. As for the racial stereotypes, that's Ishinomori's way of telling us that people have the ability to surpass national (and racial) boundaries and form lasting friendships.
Ever wonder why in the 2012 manga Conclusion: GOD'S WAR, Jet Link (002) went back to New York, his former home, and became a private detective? In the 2001 anime, an episode revealed a part of Jet's past where he felt guilt over his inability to save street children in his time from turning into delinquents like him. Working as a private detective in the place where he grew up would allow him to put away criminals, thus saving the children there from crime and allowing him to atone for his guilt.