When chief United Nations weapons inspector Hans Blix delivered his first report to the Security Council at the end of January, he drew attention to two Iraqi missile programmes, the al-Samoud Two and the al-Fatah.
Both of these, he said, had been tested to ranges in excess of the permitted 150 kilometres (93 miles).
In a move seen as key test of the Iraqi's willingness to comply with the inspectors Mr Blix demanded their destruction - a task which has now begun.
For the British and the Americans this may be as close to a smoking gun as they are going to get
This limit was set by the UN after the last Gulf war as part of the stringent efforts to contain Iraq's weapons programmes.
The development of long-range missiles capable of delivering chemical, biological, and even nuclear warheads, was seen as one of Saddam Hussein's central strategic goals.
He had already used his existing missile force against Iran, Israel, and Saudi Arabia, with conventional warheads.
It was expected that over time, Iraqi scientists would develop increasingly accurate missiles with greater ranges and payloads.
Inspectors confirmed that the al-Samoud II missile does indeed exceed the limits set by Security Council.
The fact that it has a larger than permitted diameter and that it may also have an engine derived from a surface-to-air missile are two further facts that contravene UN restrictions.
There are indications that the weapon may already have been supplied to the Iraqi Army
Both of these facts suggest that the missile could be intended to have an even longer range, since it could carry additional fuel and could perhaps be fitted with an even more powerful motor.
Iraq's missile programme, like the early stages of North Korea's and other countries' missile efforts tend to take a basic Soviet-era design and re-manufacture it, gradually extending its range and payload.
Thus, quite apart from being a violation in itself, the al-Samoud II could be the basis for further development.
And Mr Blix pointed to additional signs that Iraq had taken steps to refurbish its missile manufacturing capability.
The exact operational status of the al-Samoud II is unclear. There are indications that the weapon may already have been supplied to the Iraqi Army.
But what is going to be more controversial is the sourcing of this evidence - it seems that the inspectors learnt about the new missiles from data provided by the Iraqis themselves.
Al-Samoud missiles are based on a Soviet-era design
So is this an example of wilful disregard for the UN's strictures, or of the Iraqis coming clean on some proscribed activity?
One has to assume that the Americans already had a pretty good idea about these missile tests from satellite data. The Iraqis would know that too.
Many will say that developing the weapon does indeed put Iraq in material breach of its obligations.
For the British and the Americans, this may be as close to a smoking gun as they are going to get.