This is my very first solo play to try and get my head around the rules (and boy is my wargamming brain rusty, it hurts). I am playing Operation Compass and ended up in the following situation
It is my belief that the empty box to the east of O'Connor blocks his supply line. Is that correct?
And a related question is: do i have to combat and destroy tis empty box, or can I just roll over it to get rid of it, as per a unit moving into a vacated hex after an attack?
Is the lesson here: don't leave an unmanned box behind your line?
Well, the box is not REALLY unmanned: there is a garrison in there, too! Read the Box/Mine counter description on page 3 of the rules.
And yes it does block a Supply line. But NOT in this case: As rule 11.1 states the path to the supply source (the track leading east in this case) can be up to three hexes in length, and the Box has a parenthesized combat strength, which means it has no Zone of Control to stop your supply line. Here I have shown with red arrows the possible supply paths. If the british were instead in the hex occupied by the Italians in front of them, they would be "one hex too far" to do this stung and would then indeed be out of supply.
And you DO have to attack an "Empty" box, or advance after combat on it, to destroy it, you cannot do this in the movement phase.