We don't know what Hawking meant by "near certainty" - 90 per cent or 99,999 per cent and depending on it we may come to different conclusion about what probability it implies for next 100 years. Most readers will not do this type of calculations anyway. They will learn that global risks is something that could happen in 1000 - 10 000 years time frame. And will discount it as unimportant.
Your goal seems to be to prove that Hawking thinks thats global risks are real in near term future while he said exactly opposite.
A lot of media starts to report Hawking claims in following words: "Professor Stephen Hawking has warned that a disaster on Earth within the next thousand or ten thousand years is a ‘near certainty'. http://www.telegraph.co.uk/news/science/science-news/12107623/Prof-Stephen-Hawking-disaster-on-planet-Earth-is-a-near-certainty.html While media may be not exact in repeating his claims and the wording is rather ambiguous, he didn't clarify them publicly as I know.
About Mars. If colonies will be built by national states, for example there will be two colonies, American and Chinese, the war between US and China will result in war between their colonies with high probability, because if one side choose to completely destroy other side and its second strike capability it has to destroy all its remote military bases which may have nukes.
He did not "say exactly opposite". He said: it'll be at least 100 years before we have much chance of mitigating species-level disasters by putting part of our species somewhere other than earth, so "we have to be very careful".
My goal is to point out that you are misrepresenting what Hawking said.
If colonies will be built by national states
If these are genuinely self-supporting colonies on another planet, I think it will not be long -- a few generations at most -- before they stop thinking of themselves as mere offshoots of whateve...
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