[Olefin]

the Netherlands Marines have been posted to the Antilles for quite some time - there were there during the Cold War period and thus would have been there for the war start - they have been there to deter aggression from Venezuela since the 30's

Assuming a V1 timeline where the Cold War never ended they wouldn't have drawn down their forces there most likely

thus at war start you are looking at the 3rd Marine Battalion with three infantry companies (two on Curacao, one on Aruba) plus a company of local militia (two platoons on Curacao, one on Aruba) as well as a brigade of military police (they serve as security for both the military facilities as well as the border guard and security at the airports ) numbering around 200 or so men plus the 160 men of the Coast Guard

The militia platoons are trained by the Netherlands Marines and once trained are Netherlands Marines - thus you basically have a standing reserve Marine company to reinforce the 3rd Battalion plus reservists who used to be members of the platoons that could be used as well.

Given the fact that there were Soviet forces on Cuba and Soviet Naval units active in the Caribbean and the losses in shipping most likely the Marines stayed where they were - and the bases there might have become very important after the French invasion especially for what was left of the Dutch fleet (let alone would have been one of the last airbases they had left)

As far as nukes in South America in the V1 canon it does mention nuclear strikes against refineries in Venezuela if I remember correctly

The V2 timeline has more details including the short nuclear war between Argentina and Brazil

Keep in mind if you are looking at a 2013 timeline that force of Marines would now be only the single company at Aruba - the other two were stood down since the 90's