What if Belgian secession in 1830 failed

[nuyt]

OK, picking up this old fun WI.

The UNL / United Netherlands (minus both Luxemburgs) survive WW1, as it unravels like in OTL (with the exception of the invasion and occupation of Belgium of course).

The UNL have perfected their defences during the war due to some occasional war scares. They have their own supply of iron ore and coal in the south and are able to produce enough weapons. Fortress lines have improved, an air force has been founded. The Navy has been actively patrolling the seas towards the Americas and the (enlarged) Indies, that are booming - producing oil, rubber, rice and lots of other stuff. Connections to the colonies have been maintained thanks to the Navy and growing defences on the various islands.

Belgium in OTL was devastated after the German occupation in WW1. Many people were killed, fled the country or were taken as workers to Germany. Industries were depleted. Some scholars argue that the country in OTL never fully recovered from this disaster. That all does not happen in this scenario and growth continues right after the war.

Many businessmen flee post-Versailles Germany and bring investments, funds and talents to the UNL. Former German troops join the colonial Fuselier Corps. The relatively small country continues its upward trend and gains influence. The League of Nations settles in The Hague, not Geneva.

By the mid 1930s as Germany seeks to build up its army again, The UNL are able to act swiftly. A new generation of weapons is developed, the air force and navy are brought up to date and the colonies are well defended. Due to the ongoing boom in the enlarged Indies, the number of Europeans has doubled from 1914 to around 700.000, providing a growing pool of local reservists. The Indies by the end of the 1930s also have their own arms production facilities as well as three large shipyards, a steel forge and several oil refineries. The UNL boasts one of the largest merchant fleets of the world.

The UNL seem able to uphold strict neutrality. Can they weather a second WW?