For a certain kind of football snob, the perfect game ends nil-nil with not even a goalscoring chance. The players are distributed, and their movements co-ordinated, to reduce space on the grass for individual flair. This ideal of tactical rigour is hard to achieve in three dimensions, but the 1994 World Cup final in Pasadena was a masterclass of mutual nullification. As the US prepares to host again, it will be dreading a repeat of those 120 scoreless minutes.
There are quite enough stalemates around. The two highest-profile wars in the world are stuck. In Ukraine, an invasion that was meant to succeed within weeks is nearing first world war length. The front line moves at a hideous human cost when it moves at all. In the Gulf, the apparent mismatch between the US and Iran has settled into deadlock. Even Gaza remains a contested space. So, after more than a decade of fighting, does Yemen.