Hi Bvana,
In the years 1960 to 1976, Somalia did not recognize dual citizenship, nor did it allow for naturalization (i.e. one could not apply to become a Somali citizen). but all that have changed now as a Somali.
However, I am not sure to what extend the laws have changed but I can certainly tell that the naturalization process have changed particularly for female foreigners if they are married to a Somalian citizen. a foreigner woman can become a Somalian citizen given that her husband a Somali Citizen.
On the policy on dual-citizenship in Somalia that has also changed, now Somalia accepts not only dual-citizenship but multi-citizenship if that is applicable.
As prove of dual-citizenship in Somalia, you can google it and see that the current Somali president has himself a dual nationality as he has US citizenship and Somalian.
All of this have changed after huge Somalian diaspora formed around the World due the civil war back in 1991.
I hope that helps.
Cheers
