According to ex-US Defence Secretary Donald Rumsfeld, "There are known knowns; there are things we know we know. We also know there are known unknowns." Ridiculed at the time (2003), I've often wondered whether this was gibberish or genius-speak. On Saturday evening, everything suddenly became clear. Donald was right, I was wrong. I'm unlikely ever to get the opportunity to apologise in person, so this prose must suffice.

First the known known. Before Ryan Shawcross' mum dried her son's eyes, colleagues and his baseball cap-wearing manager leapt to his defence. He's a lovely lad. Wouldn't hurt anyone deliberately. 6-0-6's Alan Green concurred (also a known known) before imploring Arsene Wenger to shut up. Green is right, of course (for once). Arsene should be used to seeing his players' careers and feet dangling, literally, by a thread. Get used to it, Arsene; it ain't gonna change. That's another known known, in case you were wondering. What was Corporal Jones' catchphrase? Oh yes, "They don't like it up 'em!" Coincidence? Three Englishmen, playing in front of their home fans, assault Arsenal players. First Diaby at Sunderland (step forward Dan Smith), then Eduardo at Birmingham (take a bow Martin Taylor) and now this. 5Live's commentary team, who displayed pro-Stoke bias all match, even laid blame at Ramsey, suggesting he'd pulled out of the tackle!

We Gooners are all medical experts now, of course, and so as Ramsey and Ryan left the field, one hospitalised, the other apparently traumatised, I thought: Shawcross will be playing again long before Aaron even graduates to crutches. Which brings me to Saturday's known unknown and the genius of Rumsfeld's insight. On Wednesday evening, less than 100 hours after that tackle, I'll be expected to put my country before my club like never before and applaud / encourage England's debutant from The Potteries. Fat chance. It's asking something to expect me to cheer Rooney after that dive (the 2004 one, I mean) at Old Trafford effectively ended our unbeaten run - an incident that was also a known known, i.e. something that was entirely predictable, as opposed to Shawcross' England call-up, which was not.

As I texted our Esteemed Ed during play - and as he has already related - Shawcross has previous. I'm indebted to Gooner 48 for highlighting also his breaking of Francis Jeffers' ankle, when similar protestations of innocence were made. Adebayor's injury happened not to be serious after the touchline tackle from behind when the ball was already dead, and for which Shawcross was not even booked. Adebayor was back in just over a fortnight. It's no surprise that the anti-Arsenal media have not highlighted these previous acts of violence that went unpunished.

Yesterday Vidic should have been red-carded in the fifth minute at Wembley. It's a known known that Phil Dowd would not be strong enough to apply the letter of the law. The authorities have a choice: do nothing or discipline Dowd by a reprimand. If they do the former, that will be a known known; if they do the latter, it will be a known unknown. Clear?