As Trevaskis put it,

“Unfortunately, the British were ill prepared for their Eritrean responsibilities. It had been supposed that General Platt would be halted indefinitely before the heights of Keren; and consequently arrangements had only been made for the administration of the Barka and Gash-Setit Lowlands, which comprised what was then the Agordat administrative division. This, it was envisaged, would be administered by officers of the Sudan Administration as an appendage of the adjacent Sudan province of Kassala. And so, at the time of his entry to Asmara, General Platt had no more than Brigadier Brian Kennedy-Cooke (the former Governor of the Kassala province), eight British officers and nine Sudanese policemen with whom to take over the civil administration of Eritrea. […]

“Fortunately, the officials of the Italian Administration remained anxious and expectant at their posts. The only practicable course was to invite them to continue under such British control as could be improvised. […] The only department where urgent steps were taken to bring Italian control to an end was the police. The two Italian organizations — the Royalist carabinieri and strongly Fascist Polizia Africana Italiana — could scarcely be expected to enjoy British confidence as instruments of security. […] Italian uneasiness was calmed by the sight of a familiar bureaucracy attending to the routine of public business. Similarly a dangerous Eritrean effervescence very soon subsided. […]

“For this the British were largely indebted to the accommodating behaviour of the Italian officials. Had they chosen to leave their posts, not all the troops then moving northwards to help in the defence of Egypt could have been spared. Nevertheless, if this Italian collaboration helped the British to establish their authority peacefully, it also rendered them uncomfortably dependent on Italian behaviour and temper. Many Italians had access to secret caches of arms and ammunition, Italian officials held most of the principal executive appointments in the public services, and a number of hot-headed young Fascists were still at large.

[…]

Hundreds of previously laid-off Italian (Fascist) personnel were reinstated, including (contrary to Trevaskis’ account) members of the police force, spelling unmitigated disaster for Eritrean residents of both Massawa and Asmara.

(Emphasis added.)