China urged the League of Nations to stop Japan so the League; Ordered Japan to withdraw in 1931, the government agreed but the Army didn’t. Appointed the Lytton Commission to investigate in 1932, the League invited Japan to hand Manchuria back to china but Japan kept Manchuria and left the League.
The League couldn’t/didn’t do more because; the depression made countries unwilling to impose economic sanctions on Japan because this would damage trade further (the USA would still trade with Japan because they weren’t a member of the League). Collective security didn’t apply because powerful countries like Britain feared they had too much to loose by taking action, for example the British colony of Singapore would be under threat in a war between Britain and Japan.
Mussolini felt he had the right to invade Abyssinia because of a border incident between Abyssinia and Italian Somaliland (that the Italians provoked); this gave Mussolini an excuse to intervene.
In January 1935 Abyssinia asked the League of Nations to arbitrate. Mussolini refused League of Nations arbitration. Instead, four days later, he made a treaty with France – France would let Italy conquer Abyssinia if Italy would support France against Germany. The Italians army got ready to invade.
Haile Selassie requested a meeting with the league, the League banned arm sales to both sides, this hurt the Abyssinian army more than Italians who were already ready to invade.
In September, the League appointed a five-power committee to arbitrate in Abyssinia. Abyssinia rejected this because it suggested that Italy should have some land and power in Abyssinia.
In October 1935, Italy’s army invaded Abyssinia. The Italians used tanks and flame-throwers. The Abyssinians had camels, war drums and 12 planes, they were massacred.
Haile Selassie requested help from the League of Nations, the League agreed to sanctions on rubber and metals, but it did not stop oil sales. Most importantly, Britain did not close the Suez Canal to Italy, fearing that Italy might declare war on Britain, so Mussolini sent men and supplies to Abyssinia through the British Suez canal.
The League couldn’t/didn’t do more because; Britain and France were scared of war with Italy and so didn’t enforce sanctions because this might anger Mussolini. Britain and France wanted to keep Italy on their side against Germany so they did not impose any severe sanctions on Italy nor did Britain close the Suez. Instead Britain and France came up with their own solution to the dispute; the Hoare-Laval Plan in 1935.
By 1936 Italy had conquered Abyssinia and united it with Somaliland and Eritrea as Italian East Africa. Italy turned to Germany and left the League in 1937.
Collective security did not work in Manchuria because Britain had too much to loose if they started a war with Japan (e.g. Singapore). Collective security did not work in Abyssinia because Britain and France did not want war with Italy and Mussolini made a treaty with France that let Italy conquer Abyssinia if Italy would support France against Germany. Britain and France did not care much about Abyssinia they just want to keep Italy as an ally against Germany. So, collective security didn’t work because the powerful countries in the League would have rather looked after their own interests than put them selves out to look after smaller weaker countries.
The absence of America in the League made a big difference because sanctions could not be upheld; Japan, Italy and any other country under sanctions from the league could easily obtain the goods they needed from non-league members like the USA and Germany.
The actions the League took were not powerful enough to stop an aggressive country, for example the sanctions on weapons sales to Italy and Abyssinia affected Abyssinia more because the Italians were ready to invade. Britain should have closed the Suez Canal, this would have stopped Italian troops reaching Abyssinia but Britain didn’t want to risk a war with Italy.
The world’s economic climate at this time made the League’s job even harder; the world was in The Great Depression so international trade was damaged, the League didn’t want to damage trade any further by imposing needless sanctions. Also the peoples of the countries that were severely affected by the depression turned to dictators for answers, the League didn’t want this so they tried not to make the situation worse by imposing severe sanctions.
All these failures of the League of Nations other countries realised that they could also get away with aggression, this paved the way for the rise of Hitler (he re-militarized the Rhineland in 1936 and the league did not take any action) and the Second World War.