Al Shabab thrives on political conflict between regions or between regions and feds. That's why it survived in Galkacyo so well due to the division of the city. Well it does the same across the whole nation where there is division. It can operate in all territories stealthly by promising to harm the other and vice versa.
Solution is political settlement between politicians and social reconcilations between clans. The political one is easier to settle then the clan one. The political one needs constitution settlement. The clan one needs isimo to resolve all tuulo-region-federal conflicts. You also need a federal security apparatus that cooperate together to weed out shabab where there is intelligence saying so.
Finally u need to pass strict 'laws' against terrorism to warn people, any1 caught harboring, working, concealing these ppl will be given the death penalty not just the 'culprit'. The culprit had a-lot of help we need laws that treat shabab or helpers the same.