The book's references to the use of poison gas by the Martians were scary enough in 1898, but after World War I...
A similar thing happens in the Orson Welles version. Their take on the Thunderchild scene involved a bomber performing a Heroic Sacrifice by crashing into a Tripod. A tactic the Allied servicemen in the Pacific would become all too familiar with a few years down the line...
The artillery man in particular is a disturbingly prophetic figure. Even though he does not have the will to follow suit with these plans, the ideas that came up with do sound a lot like the things that thirty years latter by a group of people in Germany with good dress sense and a tendency to march without bending their knees led by a certain rejected art student.
At the year 1898, the thoughts of a war so brutal that entire cities could be destroyed to the ground en masse were considered as paranoid nonsenses and wild fantasies, especially if they were about this kind of war between the "civilized" European nations...
The Orson Welles version, which was broadcast in October 1938, took place a year later and noted that "the war scare" was over...
Unbelievably inhuman creatures with plenty of tentacles arriving from outer space, beings so immeasurably alien we don't stand a chance in fighting them, and implications of our own inevitable doom in a universe that at best seems completely indifferent to what happens to us, not to mention a certain degree of insanity that comes from realizing our insignificance. Sound familiar? Well, good ol' H.P. Lovecraft would have been a child when this book was published, predating just about everything he wrote.
The name of the military leader that battles the Martians at Weybridge and Shepperton? Brigadier-General Marvin.
The aliens that the invaders take with them as food source neatly fit the description of The Greys.
It Was His Sled: The fact that the Martians are all but unstoppable by regular means but eventually get sick and die, which is usually the case in most adaptations.
Seinfeld Is Unfunny: Alien attacks are so common in popular culture that this would not stick out to a modern reader/viewer.
The 1953 movie:
Fridge Logic: One of the first characters to be disintegrated in the 1953 film claims that they are Martians because Mars is currently at its closest approach in years. Other characters also assume this as the basis for where they come from, later on in the film. While this is true, no-one ever questions that this is only an assumption.
Genius Bonus: General Mann says he hasn't seen Dr. Forrester since Oak Ridge, indicating that they both worked on the Manhattan Project.
Hilarious in Hindsight: The creators of Mystery Science Theater 3000 swiped the name Dr. Clayton Forrester from the film's hero, and their Dr. Forrester is now by far the one more associated with the name. So watching the film in a post-MST3K world can be an odd experience.
Narm: The Martian that Dr. Forrester and Sylvia encounter in the farmhouse. Why? Not because of its appearance but because it Screams Like a Little Girl.
Science Marches On: The movie opens with impressive Chesley Bonestelle paintings of the other planets of the Solar System except for Venus. In 1953, the nature of what lay beneath that world's clouds was unknown – deserts, swamps, and global seas of carbonated water or petroleum were all considered possibilities.
Ironically, the grossly inaccurate description of Jupiter is far more telling of Venus' surface conditions.
Interestingly, Venus - forgotten in this film - was the first planet examined by a probe, in 1962.
Special Effects Failure: The terrifying and intimidating look of the Martian machines loses some power in certain shots as you can clearly see the wires holding them up.
Technology Marches On: Back in the source novel the alien war machines were vulnerable to artillery fire and a torpedo ram, which were the most powerful weapons available at the time. In this film the aliens can survive an atom bomb blast, because otherwise they would be defeated very quickly.
Reportedly, George Pal asked a Pentagon representative how contemporary armed forces would do against the Martians from the novel. He replied in no uncertain terms it would be a Curb-Stomp Battle for humanity.
Values Dissonance: The overtly Christian tone. American society was much more religious in the 1950s than it is today, so the film's Christian moralizing can feel dated and overbearing to modern viewers; particularly those that aren't religious and/or are familiar with the original novel, which didn't present religion in a favorable light.