How do Muggle Wars affect the magical world?

Question

This came up to me while I was reading the question about Magical being using firearms in battle to raise their power (which I think I have a good answer for, but it's too long to fit in this question... and it would also be inappropriate).

Anyways, I was reading it and then the following thought came into my mind: If wizards decided to use guns on their battles (the ones agains Voldemort for instance), that would create that opening for much bigger battles than we see in the books (after all even a muggle can fire a gun, so lots of guns + the Imperio curse, and presto manifesto (is that racist? talking about wizards and all) you have yourself an army). Those kinds of battles, however, would most definitely not go unnoticed by the muggles - even though they wouldn't be able to link it to magic.

Well, that thought brought up my one and final question, which I bring forth to you guys. Is there any mention on how the Wizards and Witches viewed the two world wars (which had taken part by the time Harry got to Hogwarts, and which he had probably heard about in muggle school), and what was the Wizards' part in it? What about the cold war? Did the magical world even recognise the existence of weapons such as nukes, which could render all life on earth extinct?

EDIT

DVK has brought up an answer to a previous question regarding the connections between the Second World War and the wizarding world (more specifically, the wizard Grindelwald). Although it doesn't fully answer my question, it does help by showing that there was indeed some form of connection between the two world at the time.

Answer 1

From Pottermore in the Potter Family Tree there is this:

Henry Potter (Harry to his intimates), who was a direct descendant of Hardwin and Iolanthe, and served on the Wizengamot from 1913 - 1921. Henry caused a minor stir when he publicly condemned then Minister for Magic, Archer Evermonde, who had forbidden the magical community to help Muggles waging the First World War.

JKR made these comments about World War 2 (taken from https://scifi.stackexchange.com/a/47836/1148):

JKR: I'm going to tell you as much as I told someone earlier who asked me. You know Owen who won the [UK television] competition to interview me? He asked about Grindelwald [pronounced "Grindelvald" HMM…]. He said, “Is it coincidence that he died in 1945,” and I said no. It amuses me to make allusions to things that were happening in the Muggle world, so my feeling would be that while there's a global Muggle war going on, there's also a global wizarding war going on.

ES: Does he have any connection to --

JKR: I have no comment to make on that subject.

MA: Do they feed each other, the Muggle and wizarding wars?

JKR: Yeah, I think so. Yeah. Mm.

Although, she specifically says that that Grindlewald died in 1945 (which he didn't), so I'm not sure what to think of that.

The Wizarding world was aware of the global wars, and England chose not to participate in WWI for some reason, and during WWII they were waging their own war against Grindlewald while the Muggles were waging a war against the Axis powers.

Certainly Muggleborn children who attend normal school and watch television before attending Hogwarts are going to know about the existence of nuclear weapons and other WMDs. Whether such technology is relevant to the Wizarding community is unknown.

Answer 2

World War One

Archer Evermonde 1912 - 1923 In post during the Muggle First World War, Evermonde passed emergency legislation forbidding witches and wizards to get involved, lest they risk mass infractions of the International Statute of Secrecy. Thousands defied him, aiding Muggles where they could.
_{Pottermore - Ministers for Magic}

 

Occasionally, a Potter made it all the way to London, and a member of the family has twice sat on the Wizengamot: Ralston Potter, who was a member from 1612-1652, and who was a great supporter of the Statute of Secrecy (as opposed to declaring war on the Muggles, as more militant members wished to do) and Henry Potter (Harry to his intimates), who was a direct descendant of Hardwin and Iolanthe, and served on the Wizengamot from 1913 - 1921. Henry caused a minor stir when he publicly condemned then Minister for Magic, Archer Evermonde, who had forbidden the magical community to help Muggles waging the First World War. His outspokenness on the behalf of the Muggle community was also a strong contributing factor in the family’s exclusion from the ‘Sacred Twenty-Eight’.
_{Pottermore - The Potter Family}

 

The wizards of America had played their part in the Great War of 1914-1918, even if the overwhelming majority of their No-Maj compatriots were ignorant of their contribution. As there were magical factions on both sides, their efforts were not decisive, but they won many victories in preventing additional loss of life, and in defeating their magical enemies.
_{Pottermore - Magic in North America}

 

NEWT
What, you fought in the war?
JACOB
Of course I fought in the war, everyone fought in the war—you didn’t fight in the war?
NEWT
I worked mostly with dragons, Ukrainian Ironbellies—Eastern Front.
_{Fantastic Beasts and Where to Find Them: The Original Screenplay - Scene 50}

 

BRITISH ENVOY
Scamander?
NEWT
(closing the case)
Oh—er—hello, Minister.
MOMOLU WOTORSON
Theseus Scamander? The war hero?
BRITISH ENVOY
No, this is his little brother. And what in the name of Merlin are you doing in New York?
_{Fantastic Beasts and Where to Find Them: The Original Screenplay - Scene 60}

World War Two

Question 5 out of 15
Which of the following popular historical theories have now been proven to be TRUE? Choose the correct THREE.

• A secret task force of Wizards and Muggles helped the Allies to victory in the Second World War.
• The Great Fire of London in 1666 was not, as Muggles believe, started by a blaze in a bakery in Pudding Lane, but by a young Welsh Green Dragon kept in the basement of the house next door.
• The location and name of Hogwarts were both chosen by Rowena Ravenclaw, who dreamed that a warty hog was leading her to the cliff by the lake.

_{W.O.M.B.A.T. - Grade Three (the incorrect answers have been omitted for brevity)}

 

Owen Jones: Are you implying that Dumbledore had a hand in ending the Second World War [JKR laughs] by his defeat of the Dark wizard Grindelwald -
JKR: In 1945.
OJ: - in 1945?
JKR: I may well be implying that.
OJ: Do you enjoy having stuff in the wizard world connecting with Muggle - Muggles - history?
JKR: Well, I really do, yes, because I think that's what adds to the believability of the books. I think that's one of the reasons readers can imagine themselves so readily into the wizarding world because they can see how it does interconnect with our world. So it's both secret and apparent, but we, Muggles, don't have the perception to see what's right under our noses, of course.
_{Jones, Owen. One-on-one interview with J.K. Rowling, ITV Network July 17, 2005}

 

JKR: I'm going to tell you as much as I told someone earlier who asked me. You know Owen who won the competition to interview me? He asked about Grindelwald. He said, “Is it coincidence that he died in 1945,” and I said no. It amuses me to make allusions to things that were happening in the Muggle world, so my feeling would be that while there's a global Muggle war going on, there's also a global wizarding war going on.
ES: Does he have any connection to --
JKR: I have no comment to make on that subject.
[Laughter.]
MA: Do they feed each other, the Muggle and wizarding wars?
JKR: Yeah, I think so. Yeah. Mm.
_{Anelli, Melissa and Emerson Spartz. "The Leaky Cauldron and Mugglenet interview Joanne Kathleen Rowling: Part Three," The Leaky Cauldron, 16 July 2005}