Just a few weeks ago I was in Louisiana in the southern United States for the final certification exercise of one of the US Army's newest units - the Interim Combat Brigade.
Based around a new wheeled armoured vehicle called the Stryker, this new brigade epitomises the continuing transformation of the US Army.
Transformation is the keynote for US Defence Secretary Donald Rumsfeld.
Post-conflict operations will require more troops than combat
He wants to move away from the old heavy forces of the Cold War-era to develop lighter, harder-hitting, more aggressive forces, capable of moving swiftly to a far-flung battlefield and destroying any enemy they find there.
The air-transportable Stryker that we saw going through its paces in the Louisiana woodlands fits the bill.
If the exercise is determined to have been a success, then the first Stryker-equipped unit could be on active duty in Iraq before the end of the year.
Transformation is great as a buzzword, but what does it really mean?
It involves the marriage of new technologies for intelligence and information gathering to new and ever more accurate sources of fire power.
It would then involve reorganising the building blocks of each military formation to take best advantage of these new capabilities.
Transformation is only in its infancy.
But the war in Iraq showed something of what the Americans want to be able to do.
The aim is to dominate a force in information terms - to know more about it than it knows about you - even before battle is joined.
US forces can then move swiftly to destroy the enemy, not necessarily by the individual destruction of hundreds of tanks, but by the pinpoint dismantling of its command and control.
Many experts note that Iraq also demonstrated the continuing importance of old-style heavy armour.
Indeed unease is already being voiced about some aspects of the new Stryker in terms of the protection that it affords.
But some amalgam of the old and the new is clearly where the US military is going.
Victim of its success
The problem is that in war-fighting terms, the US has no equal.
It can defeat the vastly more numerous, but inferior armed forces of a country like Iraq with only a handful of divisions.
But if you like, the Rumsfeld remedy is too successful.
Rumsfeld's remedy to reform the army is "too successful"
For winning with only a handful of divisions means that there will be insufficient forces to actually occupy and pacify the country.
This then is the lesson of Iraq - you may well need more troops for post-conflict operations that you do for war-fighting.
And if they are not going to come from willing friends and allies, then the US will have to find them itself.
That is why another word - overstretch - is being heard more and more in discussions of the US military.
The burdens of what might be called post-war conflict in both Iraq and Afghanistan are putting huge pressures on the US military machine.
The US has a staggering 368,900 soldiers overseas in 120 countries.
Nearly half the active duty force - excluding reserves - is deployed overseas.
Of these, about two-thirds are on unaccompanied tours - that is they are away from their families, unlike say many servicemen and women garrisoned in Germany.
Last July, the new US Army Chief of Staff, General Peter Schoomaker, noted candidly during his confirmation hearing that the army probably needed more people.
All sorts of proposals have been mooted - from the better use of certain reserve and National Guard units to an effort to bring more troops into the front line.
Indeed it is people rather than just money that is the problem.
Many experts argue that better spending priorities and cutting outdated programmes could free up the much-needed cash to expand the force structure, for example to move more Military Police And Civil Affairs specialists into the active force.
Transforming the US military is going to mean getting rid of - or at least dramatically scaling down - some big-ticket weapons programmes.
Mr Rumsfeld has already abandoned a heavy self-propelled gun - the Crusader - amidst protest from both within the military and from people on Capitol Hill who feared jobs going in their districts.
Several more cherished programmes are going to have to go if the money is to be found to create the new transformed military machine.
With budget deficits and a huge bill for operations in Iraq, new funding is just not available.
The good news is that the money is probably there in the existing defence budget.
It will be as much a test of Mr Rumsfeld's grit, political skills and determination as any battle.
If transformation is to mean what he says it does, he has a number of giant procurement dragons still to slay.