Eh??? Off the top of my head these countries on the list were definitely involved in WW2 “fighting” in some form:
E.g. Belgium was overrun in 1940, Brazil sent an expeditionary force to the Italian campaign, Egypt was where El Alamein was fought, Ethiopia was fought over by Italy and Britain, etc.
You need to do some reading, lad. 
Czechoslovakia and Greece definitely participated in the war as well. The Poles had partisans if my Panzer General memory serves me correctly as well:)
I believe AK84 means the countries he listed weren’t involved in fighting in the Pacific theater. Nevertheless, they had declared war on Japan.
Personally, I’m a little unnerved by the thought that Luxembourg and Japan might still be at war. I have this vision of samurai laying siege to the Grand Ducal Palace.
Of course, the United States was fashionably late to the party, as it was previously in 1917. For many countries the party started in 1939, 1938, or even earlier (e.g., for China and Japan).
And, as others have said, Japan and Russia are still technically at war with each other.
Ah yes, think you’re right. Sorry AK84.
The alternative might be even more interesting – undercover operatives of the Grand Duke, disguised as tourists, capturing Akihito and holding him for a ransom that Japan can afford and which turns Luxembourg back into a major power. A writer like Leonard Wibberley could do a lot with this concept! 
And it is extremely interesting what the practical politics behind this was – and, amazingly, the SDMB and I were tangentially involved in its becoming public.
For many years, King was looking for ways to “untie the apron strings” still in place after the Statute of Westminster. When Chamberlain advised the King to declare that a state of war existed between the U.K. and Nazi Germany, Britain had been importing arms and ordnance from the U.S., with Roosevelt’s support, that would need to be terminated when Britain went to war until the U.S. Neutrality Act was amended (as it soon was).
Accordingly, Mackenzie King withheld the Canadian declaration of war for six days, while shipments of arms to Canada – which was arguably a separate country and still neutral – were pushed across the border with top priority. P.M. King was most happy to do so, as, while he supported the war, this made it very clear that Canada was a separate nation, not controlled by the actions of the U.K. Britain and the U.S. were happy, since it enabled the “aid to Britain” policy to be continued without violating U.S. law. And the whole thing was kept completely sub rosa to avoid angering isolationist and anti-war groups in both North American countries.
It was widely believed by historians that King had withheld the declaration of war simply to make the point that Canada was an independent nation with a separate foreign policy – and nobody in the know contradicted this, for many years.
How this finally came out, ironically, was on the retirement of the longtime chairman of the Thousand Islands Bridge Authority, he gave an interview in which he described how, on Britain’s declaration of war, he got a call direct from the White House directing him to give top priority to arms being shipped from the U.S. into Canada across the bridge. I heard this interview, recognized the implciations, and something over a decade later, reported it here in the midst of a Great Debate on WWII.
Perhaps a year later, discussions on the beginning of World War II began reporting King’s real motives – both the long-known one of establishing clearly Cabada’s autonomy and the ‘hidden’ one of advancing the war aims of all three countries. I cannot help but feel there is a connection there.