Analysis on the Spanish invasion of Portugal of 1924
By the Joint Committee of Strategic Analysis of the Army Staff of Iberia
Debriefing
Spanish forces crossed the Portuguese border without meeting opposition and occupied its first objectives. Portuguese forces were unprepared and disorganised and failed to establish defensive positions along the route or in any strongholds or defensive positions available to them which could have easily blocked Spanish advance.
The Spanish Army elements continued to carry out their plans without suffering more than light casualties when meeting with organised defence in few crossroads along the way. 1st Corps, attacking from the North directly towards Porto and Lisboa encountered the most resistance, whereas the 2nd and 3rd Corps, attacking from the East and South respectively, were only slowed down by occasional security posts improvised in roads devoid of any kind of traffic and located in topographical accidents, resulting in light losses for a few battalions.
Portuguese forces never put up a true resistance, leading to a total and complete collapse of the Portuguese government at the hands of Spanish forces.
Conclusions
Although unstopped, Spanish advance was slowed down by simple and basic defensive structures set up by Portuguese forces. As such, a confrontation against a more organised enemy would have easily led to a Great War-like stalemate, with trench warfare and heavy and sustained losses.
As well-planified as the invasion was, a minimal organisation of enemy forces would have led to a long war of attrition which, in the present case, would have been avoided with an amphibious assault on Lisboa.
In order to enhance the military performance of the joint Iberian army, this committee establishes that it is necessary to develop the army towards acquiring greater mobility and higher speed, in order to avoid the possibility of entrenched stalemates. It also suggests that this should be done through the adaptation and development of vehicles similar to those used to break entrenchments in the Great War, known as landships.
The Committee also encourages the further study and development of amphibious warfare as used in the Alhucemas landing.
