why was switzerland not invaded in WW1 or WW2 sure they were neutral but so was Belgium and that didn't stop Germany?

Bottomline; the Swiss can easily defend their country given the Alps are as formidable a defense as the Channel was for England, and given the economic benefit Switzerland was to Germany [eg much of the pillaged gold and assets from the Holocaust victims disappearing into secret Swiss bank accounts] combined with the cost invading Germany would have paid it just wasn't worth it.

"With Hitler’s rise, the Swiss feared a German invasion and tweaked the National Redoubt (the Swiss national defense plan). They installed defenses (like the Toblerone line) that were intended to slow down an invasion enough to allow it the military and government enough time to withdraw into the easier-to-defend alpine areas. Switzerland built oodles of forts (most camouflaged like Fürigen)in the center of the country (we’re hoping to visit more of them).

Why buy the cow when you can get the milk for free? Germany was able to use Switzerland’s train lines to Italy during WWII. We’ve all heard about the sealed rail cars that passed unchecked through Switzerland from Italy to Germany. The Swiss rigged every bridge through the mountains with a incendiary devices, destroying the valued Swiss supply lines. Switzerland also made economic concessions to Germany. They hoped Germany would do a cost benefit analysis and decide that it wasn’t worth it.

Switzerland conducted a delicate and escalating dance with Nazi Germany. For example, Germany continually violated Swiss airspace. Germany threatened the Swiss after they shot down 11 Luftwaffe planes (that were flying over Switzerland). The Swiss army ordered this stop, they forced the planes to land at Swiss airfields instead. Hitler (unsuccessfully) sent saboteurs to destroy the pesky airfields. Relations on a personal level (with bankers) were a little less tense."

Switzerland was Germany's bank, the Alps have little to do with it.

Belgium was in the path for their attack on France, Switzerland wasn't. The Germans didn't need it, so why spend the men and material to take it and hold it? Sweden was right across the Baltic Sea but Germany didn't take it either. The Swedes simply made the decision early that whatever the Germans wanted the Swedes gave willingly. Most of Gemrany's iron ore came from Sweden. After November 1943 the Swedes also made most if not all of Germany's ball bearings, for their equipment.

Because Switzerland was used by thw Nazi party to process all the money looted from the Jews as well as Millions of valuables stolen from Museums , Cathedrals, etc.

Well when the Nazi wanted to buy raw materials in Neutral and non axis countries they needed a banking system that could transact with non aligned suppliers.

Specials metals from Spain, raw and industrial parts form Sweden, chemicals from America, food from South America, Rum from British Jamaica, Industrial diamonds from South Africa, ect,ect.


So to commercially interface with suppliers one needed a bank, so what would be better than a bank in a country that has the best baking system in the world, namely Switzerland.

Invading them would be like shooting one's big toe off. So channelling L.G Farber's profits form their American subsidiaries of Dupont, would go of cause, through a Swiss Bank.

B̶e̶l̶g̶i̶u̶m̶ ̶i̶s̶ ̶a̶n̶ ̶a̶r̶t̶i̶f̶i̶c̶i̶a̶l̶ ̶c̶o̶u̶n̶t̶r̶y̶ ̶w̶h̶i̶c̶h̶ ̶o̶w̶e̶s̶ ̶i̶t̶s̶ ̶e̶x̶i̶s̶t̶e̶n̶c̶e̶ ̶t̶o̶ ̶t̶h̶e̶ ̶c̶o̶n̶t̶i̶n̶u̶o̶u̶s̶ ̶c̶o̶n̶f̶l̶i̶c̶t̶s̶ ̶b̶e̶t̶w̶e̶e̶n̶ ̶F̶r̶a̶n̶c̶e̶ ̶a̶n̶d̶ ̶G̶e̶r̶m̶a̶n̶y̶.̶ ̶ ̶S̶i̶t̶u̶a̶t̶e̶d̶ ̶o̶n̶ ̶t̶h̶e̶ ̶m̶a̶i̶n̶ ̶i̶n̶v̶a̶s̶i̶o̶n̶ ̶r̶o̶u̶t̶e̶ ̶i̶n̶t̶o̶ ̶F̶r̶a̶n̶c̶e̶,̶ ̶i̶t̶ ̶w̶a̶s̶ ̶d̶e̶s̶i̶g̶n̶e̶d̶ ̶t̶o̶ ̶a̶c̶t̶ ̶a̶s̶ ̶a̶ ̶'̶t̶r̶i̶p̶ ̶w̶i̶r̶e̶'̶,̶ ̶ ̶a̶n̶y̶ ̶i̶n̶v̶a̶s̶i̶o̶n̶ ̶o̶f̶ ̶B̶e̶l̶g̶i̶u̶m̶ ̶b̶y̶ ̶e̶i̶t̶h̶e̶r̶ ̶s̶i̶d̶e̶ ̶a̶c̶t̶i̶v̶a̶t̶e̶d̶ ̶t̶h̶e̶ ̶m̶u̶t̶u̶a̶l̶ ̶d̶e̶f̶e̶n̶c̶e̶ ̶t̶r̶e̶a̶t̶i̶e̶s̶ ̶s̶i̶g̶n̶e̶d̶ ̶b̶y̶ ̶o̶t̶h̶e̶r̶ ̶c̶o̶u̶n̶t̶r̶i̶e̶s̶.̶

Switzerland has a distinct political history going back over 500 years, its neutrality was a prerequisite for its existence. Mercenaries from what is now Switzerland had been major contributors to the warfare in Central and Western Europe, and by international agreement no Swiss citizen was allowed to take part in future conflicts.
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As @Salty dog has pointed out, my answer consists mostly of bollox.

they are bankers and neutral they deal in money human life is not part of the equation the Nazis and the USA had accounts next to each other such is capitalism cold cruel heartless like it's clients the banks are neutral

Belgium was a strategic area and the Nazis needed it to progress.

Switzerland was the SS bank IBM had Offices there to collect its NAZI profits

Switzerland like the USA sold war Goods to Germany Standard Oil sold Oil Fuel Ammunition and Food to the Nazis up to 1945 Via span and Switzerland

During Operation Paperclip where 10,000 Nazis escaped via the vatican the cost was paid in Swiss Franks 400,000 Gold Swiss franks sent to the Vatican from Nazi Bank accounts to Fund the Escaping

Switzerland has a formidable mountain range called the Alps.
Rugged landscapes present multiple difficulties to an offensive operation. Ambushes lurk around every ravine, it's very difficult to haul cannon up steep slopes, and so on.
In WWII Swiss banks held the fortunes of top Nazis, who may not have wanted their money endangered.

Militarily Switzerland. wasn't worth the trouble. For the armies the terrain of extreme jagged peaks (& low population density) is hard to fight in or for. In this respect it is very much unlike Belgium.

It held no strategic importance to any side in either war. It also held great wealth in trust from both sides in the second world war, have to love those numbered bank accounts.
No one actually wants to fight mountain warfare.

Tactically it didn't make sense to invade Switzerland in WW1 - the aim of Germany was to deliver a 'knock out blow' to France within 40 days - before the Russians (who Frances were allied to.) could mobilize it's army. The French had built defencive fortifications along their eastern border...except for a gap on the Belgian border (due to Belgian protests). Germany reasoned that by capturing Paris, they could defeat France and by going around the Northen flank of the defences would be quicker and easier than going to the south.

In world war 2, it was different, there actually was a Nazi plan - operation Tannenbaum - to invade Switzerland and partition it (German speaking area's would become part of a 'greater Germany', the French area was to be turned into a vassal state - effectively a Nazi holiday resort, and the Italian areas would have been passed to the Italians.). However, The Swiss changed tactic's from purely static defences to a

Militarily not so useful to try a route through Switzerland. That country is full of mountains, difficult terrain for a rapidly-moving troops. Belgium is mostly flat, or with gently rolling hills.

ever hear of the Alps?

They werent part of Germany's plans.