Libya: Military advisers unlikely to herald occupation
Throughout the history of military intervention, the injection of military advisers has preceded an escalating commitment of manpower.
In 1975, a handful of Soviet military advisers were sent to Afghanistan; by 1978, there were more than 3,000; within a decade, well over half a million Soviet troops has passed through.
US involvement in Vietnam also began with a small advisory mission in 1950. It expanded to 750 in 1955, and 16,300 by 1963.
This reflects the inherent difficulties of long-distance regime change, and the excessive and usually disappointed hopes placed in modern air power.
Legal and understandable
Five weeks after bombing began, the inept rebels remain hemmed into eastern Libya, unable to exploit the destruction of a third of Muammar Gaddafi's heavy equipment.
In Misrata, the nature of urban warfare and limited ground-attack assets means that Nato cannot break the siege - at least not at an acceptable cost to civilians and infrastructure.
The UK has sent body armour and communications equipment to the opposition, and oil export revenue will soon start flowing to them too - all to no avail.
This is what has prompted the UK, France and Italy to send advisory missions to the rebel Transitional National Council (TNC) in Benghazi.
The UK's insistence that this is "non-lethal" assistance, directed at improving organisation, communication, and logistics, is untenable, since the ultimate effect will be to improve the rebels' military strength.
This is both legal, since the teams will not comprise a "foreign occupation force", and understandable, since rebel pressure is one of the few means by which the regime might be persuaded to pull back and negotiate.
The advisory teams furnish European states with (highly limited) leverage over rebel aims and strategy.
Their deployment also sends a powerful signal of resolve to Gaddafi that, whatever the divisions within Nato, there is a core of countries with a genuine stake in the fight.
But will this be effective? First, it requires defining the rebels.
The rebellion's military command is split into two - between Gen Khalifa Haftar and Gen Abdul Fatah Younis - and it is not clear which faction the Europeans will be engaging.
Assistance should be predicated on the rebels agreeing to a clear and unified command, under absolute civilian control.
Civil wars always embolden charismatic military commanders, meaning that - as in Afghanistan - post-conflict warlordism can be a malign by-product, hindering a constitutional settlement.
This is worse when insurgents splinter into competing factions. As the war extends, that risk increases.
Second, even with these precautions, training rebels is fraught with difficulty.
Such small numbers of advisers are unlikely to be able (or allowed) to improve small-unit tactics and weapons-handling.
But in modern warfare, it is these basic doctrinal factors - how to move in dispersed groups, use suppressive fire, and hold forces in reserve - that trump technology or numbers.
Third, assistance takes time.
Nato has spent many years and enormous resources actively training the Afghan National Army, but it remains a dysfunctional and largely ineffective fighting force.
The opposition will remain deficient in combat power for at least two months, during which time alliance unity will continue to fray, and national parliaments - including the UK's, which has been in recess - will agitate for proper consultation.
Nor can these advisers do anything to alter the course of street fighting in beleaguered Misrata, far to the west.
A resilient regime, squabbling rebels, and ineffective military advisers - these are ominous signs that have, in the past, heralded escalation. But the Vietnam and Afghanistan comparisons are likely overblown.
The war in Libya plays out in the shadow of Iraq's urban warfare and Afghanistan's raging insurgency. Basra and Helmand were not catastrophes, but they were failures.
No British policymaker or bureaucrat with any influence wishes to repeat the experience.
Moreover, the two pillars of intervention have been legitimacy and legality, afforded by the Arab League and UN Resolution 1973 respectively.
A serious discussion of ground forces would shatter both, ensure that the US withdraws further to the sidelines, and dissolve electoral support for the war in Europe.
Even a small force to secure Misrata's port - as advocated this week by former British Foreign Secretary Lord Owen - is implausible.
Since there is no prospect of Arab support for European boots on North African soil, and Russia would categorically veto any new resolution, the UK and France are operating under tight, but well understood, constraints.
Though advisers may make little dent on the war, they are exceedingly unlikely to be joined by large numbers of their compatriots.
Shashank Joshi is an Associate Fellow at the Royal United Services Institute (RUSI), a defence think-tank in London, and a doctoral student of international relations at Harvard University.