Sidewinders From Sirius

The treacherous aliens from Outer Space gave Earth six months to surrender or be destroyed ... but Vice-colonel Gaylord Kram, fearless ace of Terrestrial Intelligence, had a daring plan: Why not surrender now ?
Gaylord Kram, Vice-colonel of Intelligence, Terrestrial Federal government, sat pondering one of the worst poker hands he had ever witnessed, and he had witnessed a goodly number in his 38 years, when he should have been sweating blood over his tottering government's most perplexing problem: what to do about the colonists from Sirius and their G-ray.
But what could even a Kram do with two deuces, the joker, a five and an eight-spot, all of different suits?
The other three Intelligence officers who were taking a little badly-needed recreation the old fashioned way weren't too surprised when Kram raised a thousand credits. There was no sense in trying to analyze Kram's poker, any more than there was any sense in trying to analyze Kram. He usually won. Always a different technique, but he usually won anyway.
Major Ignacius Luverduk, Kram's somewhat useful assistant, knew this and folded his lowly hand which consisted of nothing more than dogs-over.
While he was waiting for the colonel across from him to up-ship or get off the runway, Kram fell to thinking.
Xenthl had pulled a dirty one. Forty years ago, the people of Iaaro, system of Sirius, under the too-able leadership of Xenthl, had finally made their presence known on Earth. For three centuries, they had examined Earth from afar to assure themselves that it would make a suitable landing spot. For awhile, during the mid-twentieth century, they had scared the pants off some people and incurred the ridicule of some others less imaginative with their disc-shaped space and aircraft, but that couldn't have been helped. One had to trace a culture, a civilization, for a long time before one could analyze its true character-traits, abilities, potentialities. Especially when one's forces were few in number, and there were nearly two billion of the other fellow.