Ethiopia has had some sort of relations or presence in the region since Aksum is what I'm saying. Of course influence was two ways, no one said otherwise. But there was basically no contact with Southern Somalia until the modern period.
To expand on the point about Italian v. British colonial influence on Somalia, I think it's important to note that the British left Somaliland to its own devices whereas Italy attempted to turn Southern Somalia into a prize colony. The British take on their role in Somalia: "We will only seek to minimize conflict in our area, we will not invest or capitalize from the occupation. The only thing worthwhile about our occupation is its strategic location, so we will be hands off except when it comes to conflict avoidance and resolution." The Italians: "We will invest a lot in our area of Somalia, we will modernize and begin development in the urban areas such as Mogadishu, we will displace a lot of people and have them work in the city to disrupt and fundamentally alter traditional lifestyles, in an ultimate attempt to terraform it for our purposes."
Somaliland gained independence from Great Britain on June 26, 1960 (today's the 50th anniversary btw)...Somalia gained its independence from Italy on July 1st 1960. Therefore, Somaliland was a sovereign and independent country for 5 days.