In a random discussion with some of my work collegues it was suggested that africa is gradually becoming the external military base of the usa ,nigeria included,

How true is this, and to what extent.

This is very disturbing, as to my knowledge if a country has financial resources such as oil and is not in the good books of the western super powers and is not abiding with their rules , such a counrty is a bad investment plan because the west will go to war with it eventually and underrmine the very fabric of that economy.
What is your intake on this matter?

The US has pockets of military bases across the world and the strategy is to be able to deploy its forces as quickly as possible to quell any uprising or threats to its interests worldwide. Those interests include, but are not limited to, the investments of its private sector in other countries. Also, because of the country's seemingly insatiable demand and consumption of energy, it becomes paramount that it protects and secures the sources of the energy that its economy is very much dependent upon to avoid any adverse effect on its economy. Fact: 20% of the world energy production is consumed by the US alone. (This may have changed following the rise of China and India as economic power house.) This reason, more than anything else, analysts believe, is the motivation or drive behind the push to have a base in the Bright of Benin to look after the Nigerian Delta and the Equatorial Guinea both of which are known to have vast amount of oil reserves.