Triangulation

After 1.Kd5  Kc8,  2.Kd4! White is now ready to meet 2...Kc7 with 3.Kc5 and follow it up with 4.Kb6 winning Black's a6-pawn.

2...Kd8, 3.Kc4 (still waiting for 3...Kc7).  3... Kc8,  4.Kd5 Kc7 and now we have the the position in the diagram--but with Black to move.