Why the ICC is not investigating crimes against humanity by Warlords,Al-Shabaab and Ethiopian Army?

In the year of 1993 the Somali Jurist association in a letter given to UNITAF( the international forces) and the United Nations which were running the country under a U.N Security Resolution asked for Accountability for the Human Rights abuses and war crimes committed during the Civil war by the Warlords and organized groups including the Siad Barre regime which collapsed 1991.It was discussed at the first Humanitarian conference organized by the U.N made in Addis-Abeba that same year but unfortunately the Somali groups/Warlords which were controlling spates of territory sub-divided in Sub-Clans refused any accountability for the crimes committed  during the 1991-93 period. I believe this warlords which were supported by Ethiopia mostly did not wont any real peace and reconciliation at that time nor they wont it now. A lot of water has passed under the bridge and the crimes have multiplied ten times and we are at a point that everybody believes that the" Norm  is impunity" if you are an officer  in the so-called TFG or so-called regional states. The Ethiopians and IGAD have adopted the same culture of killing Somalis as they were Colonial forces trying to subjugate the people-citizens. I am writing about this groups because they are signatories of international covenants on human rights and the officers of Somali government are under also international Laws concerning the rights of Somali-citizens even when the State is Failed like in Somalia. Still armed militia representing different groups who says are representing Authorities are killing people-citizens and for the last four months five journalist have been killed in Somalia including the region of Punt land.There is also the Al-Shabaab which is committing heinous crimes all the time against children and women like everybody and it also committing crimes of war,act of terrorism.But the main problem is that from 2004 the Meles regime and IGAD have sanctioned for Somalia a political architecture were the Warlords-Drug-Barons are the ultimate powers in Somali State  affairs.Be it in  the so-called state regions and the TFG.During the Ethiopian occupation of Somalia of the 2006-2009 the ethiopian army have killed 17.000 Somali as has been reported by Human rights watch and Amensty international.Maybe lets say 10.000 thousands( I am giving the benefit of the doubt to the ethiopians) were enemy combatants of Al-Shabaab but what about the rest which is more than 7.000 thousans civilians? why they have to be killed in in- discriminatory way?    Why the U.N and all international Human rights organization have not done anything about Somalia all this years? What kind of hidden agenda is at work? the United Nations security Council must pass a mandate in which all crimes against humanity ,all rapes aganist women ,recruiting of children in militias, the indiscriminate killin of civilians by Warlords and all Shabaab must be investigated and prosecuted by ICC.If we don't have justice and the perpetrators of all that injustices/crimes  are the "puppet leaders" installed by Ethiopia and IGAD for the Somali Republic how we can  have Rule of law and a funtioning federal  State? The London Conference as "usual" has accepted and sanctioned the warlords/Drug-barons,'puppet parliamentarians" installed by Ethiopia to also run the next government of Somalia after the 2012 August mandate.Wait and see.