About 800 people died in Nijmegen — as many as in the Nazi destruction of Rotterdam. Thousands lay wounded. Enschede, Arnhem, and Deventer, each also near the border, also suffered Anglo-American bombardment on what many Dutch people consider to be the worst day of the Second World War.

The attack struck Nijmegen — a Batavian-Roman city about 4 kilometers inside the Netherlands across the border with Germany — from a clear blue sky at 1:30 in the afternoon, obliterating most of the inner city and eliminating its train station.

The so-called "keizerstad" ("city of the emperor [Charlemagne]") lay in ruin. The "jewel of Holland," arguably the oldest city in the Netherlands, fell into rubble within a few minutes of immense bombardment.

"Operation Argument," the mission that went awry on that day, was an immensely complicated plan, the largest Allied bombing run to that date, intent upon the total destruction of the German airplane industry.

Hundreds of bombers were to fly in coordinated groups of smaller coordinated groups, in a pattern of movement that would be difficult with modern technology on a clear day in peacetime.

Aside from the deep complexity of the task of moving hundreds of bombers into combat, the weather conditions that the mission would require were specific. "Operation Argument" would need a deck of clouds over England and clear skies over Germany — clouds to obscure the formulation and departure of battle-groups, and clear skies to allow visual targeting of objectives. Plans would have to be sychronized — and yet would have to wait, for a command that would order thousands of people into action on short notice calibrated upon prediction of the weather — an elusive science for anybody.

The Americans had developed a method of large-scale bombardment that was more effective — but more complicated — than that of the British.

The British had been overflying targets in the form of a queue — a straight line, tip to tail. This method, clearly easier to plan, made easy targets of any but the first several craft.

In the American sytem, battle groups formed around the element of three airplanes — one in lead; another behind, right, and above; the other behind, left and below. Four groups of these, and three groups of those groups, would make an arrangement of 36 craft that would appear from ground-level to be flying almost at wingtip to each other.

These 36 bombers in formation, a "battle group," could overfly a target within moments, and at the command of the lead craft release a massive load of ordnance with an advantage of surprise.

But the organization and movement of such formations — difficult in ideal conditions — went horrifically wrong over The Netherlands on 22 February 1944.

In order to form the battle groups, individual planes departed a given airfield, one or two every minute depending on conditions, and rose in a great circle around a vertical radio beam which coordinated their arrangement "in place." This battle group would then depart for a second position above another vertical radio beam, where the group would form position relative to another battle group — and in this way organize the pattern for onward movement, into territory where the radio contact would be strategically limited.

Over Germany, each battle group had a list of three targets arranged in order of priority. The primary objective of the day was the aircraft factory in Gotha, not far across the border, and the larger goal was the total destruction of Nazi air capability. In case the primary goal was unachievable, the battle group was to fly onward and attempt goal number two, and of course the same directive would apply onward to number three.

If none of the three pre-selected objectives were achievable, the leader of the battle group would be under orders to select a "target of opportunity."

The clouds that unexpectedly covered every specified objective over German territory that day seem to have been the doom of the unfortunate eastern Dutch cities on that hard day — that and the bad fortune of the error of humans under great stress on a mission of extreme complexity.