If Britain or Nato were ever to contemplate a military intervention in Somalia, it would be incredible. And any hopes that even a lesser role in the country would be successful must be met with scepticism. Not because there aren't already foreign influences in the Horn of Africa nation – at the latest count there are five armies there – but because in all the decades of outside interference there hasn't been a single success.

The Cold War squabble over Somalia turned the country into an arms dump and helped foment a civil war that has raged ever since. The US mission in 1993 was such a debacle that it deterred the Clinton administration from any African intervention to the extent that it ignored Rwanda's genocide.

The Ethiopian invasion five years ago acted as midwife to the birth of Islamic militants al-Shabaab as a national force and ended in bloodied retreat. The Kenyan campaign launched two months ago was strategically disastrous and already looks doomed.

Somalia's clan system and its fluid alliances regularly make a mockery of outside experts, the only clear rule being that politics and conflict in the country is always local. National unity is possible but has only recently been created by resentment against foreign invaders.

Conflict in Somalia is more complicated than a fight between al-Shabaab and a UN-backed government. By backing the corrupt and useless transitional federal government, which is dominated by one side of Somalia's previous civil war, the West has already entered a more complex fight than it publicly acknowledges.