Final answer:
Europeans did not use military cooperation against Muslim Arabs as a pretext to penetrate the interior of Ethiopia. They utilized other strategies including scientific research, commercial expeditions, and religious missions. The discovery of quinine and technological advances were vital in overcoming earlier obstacles like malaria and the difficult terrain.
Step-by-step explanation:
The pretexts Europeans used to penetrate the interior of Ethiopia included scientific research missions, geographical and commercial expeditions, and religious missions and explorations. However, one pretext that was not used was military cooperation against Muslim Arabs. European incursion into the African interior had historically been limited due to factors such as the lethal disease of malaria, the challenging African terrain for equine conquest, and the strength of coastal states. It wasn't until the discovery of quinine to treat malaria, and advancements in technology like mechanized vehicles and advanced weaponry, that Europeans effectively began to establish control over Africa's interior regions.
The Portuguese, driven by religious zeal and the pursuit of wealth, were among the early Europeans attempting to explore Africa. They had myths of an African Christian kingdom ruled by the legendary king Prester John, and they sought an alliance with this kingdom to counter the Islamic forces. However, before these more organized efforts and the Berlin Conference of 1884 that would carve up African territories among European powers, many Europeans succumbed to diseases and the harsh African interior conditions, which earned Africa the moniker "white man's graveyard" until the later 19th century.