Crude similarities between World War 1 and 2 I can think of: relatively high rate of fire rifles, machine guns, artillery, tanks (barely), and somewhat developed navies. To me these similarities would mean the two wars take similar paths strategically.
Of course WW1 did not have much of an air scene at all, but I don't think that matters much when thinking about trench warfare. France even seemed ready to go with slow drawn out warfare with their maginot line.
I'm just guessing the reason there wasn't much trench warfare was the advent of Germany's blitzkrieg. It just didn't give the opposing sides enough time to dig in. Was that the intention?
^ These answers I've given previously should be pertinent.
Crude similarities between World War 1 and 2 I can think of: relatively high rate of fire rifles, machine guns, artillery, tanks (barely) ... To me these similarities would mean the two wars take similar paths strategically.
The problem here is in assuming that Trench Warfare was in any way par for the course in WWI; it wasn't. The Eastern Front, the Balkan Theatre and the Middle East all saw mobile/semi-mobile operations, with a fairly operational tempo. The trenches at Salonika, on the Isonzo Front, and at Gallipoli were imposed by the terrain and logistical factors, but in the end fighting at the former two became fairly mobile by the end of 1917.
Only the Western Front saw combat reduced to a trench-based stalemate, and not for as long as one would think; really only from November 1914 to March 1917. The fighting on the Somme, and also at Verdun, in 1916 set the tone for the rest of the war. The Somme and Verdun débuted offensive systems used by both armies, but it was the Somme that best demonstrated Franco-British Set-Piece Attack methods, while Allied artillery and air superiority during that campaign made it suicide to cling to static, trench based defenses. From march 1917 onwards, following the completion of the Withdrawal to the 'Hindenburg Line', German defensive methods centered on elastic defense in depth, using bunkers, pillboxes and dugouts supported by obstacle belts to slow down an enemy advance, before unleashing the reserved infantry in a counter-attack to recover lost territory. Fighting in 1917 became semi-positional or 'open' warfare, no longer confined to the trenches, but no yet high-tempo maneuver warfare.
Of course WW1 did not have much of an air scene at all, but I don't think that matters much when thinking about trench warfare
Ludendorff would beg to differ it seems:
At the epoch-making conference at Cambrai on 8 September Ludendorff argued that 'artillery and flyers must be brought closer together. A combat high in the skies brings them the prospect of high decorations and mentions in dispatches, and has become more attractive and splendid in their eyes than the business of observing for the artillery, which we have not got at all right. An understanding of the high importance of artillery spotting is something which can be awakened only over the course of time.'
The Somme saw the birth of air superiority; aggressive Franco-British air forces provided reconnaissance, directed artillery, coordinated advances, and carried out strafing attacks and even some bombing attacks. WWI itself saw the birth of air power, and it was the development of metal, monoplane aircraft, with more powerful engines and armament in the 1930s, that precluded any return to static trench warfare, among other things.
I'm just guessing the reason there wasn't much trench warfare was the advent of Germany's blitzkrieg
I could go into how 'blitzkrieg' wasn't actually a thing (ie doctrine, strategy, etc), but in short, German armoured warfare was based off new technology (ie wireless radios), mixed with armoured fighting vehicles like tanks, built around previous German maneuver warfare thought and the writings that emerged from the 'Armoured Idea' writers of the 1920s and 30s.
Armies were more motorized and mechanized, possessed massive amounts of firepower, and possessed the wireless communications to make snap battlefield decisions, while being supported by air forces that could interrupt/interdict enemy movement on the ground.
That said, there were campaigns like the fighting on the Gothic Line and the Winter Line in Italy 1943-44, and the Rzhev Salient and Demyansk Pocket/Salient from 1942-43, and also the Iran-Iraq War, that saw widespread positional fighting. The Normandy campaign was almost reduced to this, and it took months of bloodshed and resorting to massive amounts of artillery, naval gunfire, and bomber support to finally break the deadlock with Operations Cobra and Totalise.
France even seemed ready to go with slow drawn out warfare with their maginot line
The French expected a drawn out campaign (as did Halder and the Wehrmacht) before being able to go over to mobile operations. The point of the Maginot Line was to economize French manpower and force the Germans to repeat August 1914, ensuring Belgian and British support and allowing the French to 'telegraph' the German advance to an extent. What they did not expect was to lose air superiority at the opening of the campaign, and to encounter the bulk of Germany's armoured forces pouring through the Ardennes, which wasn't exactly 'tank country'.
TL;DR: Tanks, Aircraft, Wireless Radio, and greater Firepower in general