\ / \ / / / \ / \ (gun) \ \ \ (gun) Mutual support
Siting weapons this way is an case of the application of the defensive principle of reciprocal trend lines. the benefit of siting weapons that reciprocally trend lines of these an additional is that these are hard for an assailant to locate a covered approach to any a single defensive position.

Utilise of armour, air trend lines, indirect fire trend lines, & stealing come maneuver that can be utilized to assault the defensive position. But whenever combined by having l&-mines, snipers, barbed wire, and air handle, crossfire became the hard manoeuvre to counter in the early 20th century.

Trench warfare
A tactics of applying overlapping arcs of fire come to prominence in the period of World War I where it was a feature of trench warfare. Machine guns were placed around groups, known as machine gun nests, & it protected a front of the trenches. Several populates were misplaced around futile tries to charge through a no man's land where these crossfires were set up.

A significance of crossfires is that it rendered useless what experienced been a virtually all effectual weapon of warfare since a Greek phalanx: massed foot. Though World War II had other casualties overall, a relative dull of deaths around comparison a total of soldiers wwhen additional than twice when high in WWWe, & a soldiers died lot more quickly in a battles of Globe War I as it went "over the top" within to the meat grinder called there is no human's land.

3 items changed between WWI & WWII that rendered a crossfire obsolete: a advance of armoured vehicle (especially tanks), a advent of aerial bombardment, & a invention of the proximity fuse.

Tanks were invented within WWI specifically because it were resistant to machine gun fire, & may so cross there are no human's land to kill a machine gun nests. Their panoplied hulls as well provided handle for a foot to advance in the area of the tanks. A tanks inside WWI were ponderously slow & prone to stalling, even then, so it tipped a balance in the favor of the British, but not decisively. Withwithin WWII, the tanks improved greatly in speed & reliableness, & can email a machine gun nest at decreased chance since it spent less period contaminated.

Plane were present around WWI, however it were utilized primarily for recon & a effect of the battle in everyone's thoughts didn't have a lot of burden on the ground battle. A pilots typically experimented by using carrying items such as hand grenades to drop on the enemy, however it were largely uneffective. Within WWII plane can bomb enemy lines, giving any big stationary target vulnerable to destruction. Fighters besides strafed enemy lines by using machine gun fire.

the proximity fuse allowed bombs & munitions to detonate whilst an object passed inside a certain range (ordinarily astir Fifty feet (Fifteen m)) like than utilizing an impact or even timed fuse. Timed fuses come tricky because a range has to exist as pre-predetermined right. Impact fuses come bad against flying targets because it have a super little targeting silhouette, & it're badness against ground targets because a projectile has period to embed in a ground prior to it explodes, deflecting the explosive power upward. Proximity fuses were developed per U.S. Navy around a period of WWII, & it proved subservient in defending a fleets from either either aerial attack since a machine gunner utilizing bullets by owning proximity fuses sole got for just about hitting the enemy to knock him from the sky. Proximity fuses were besides implemental in a battle for Britain because, when a cannoneer changed to proximity fuses, non one German bomb mass produced it past the guns. A fuse too permitted a heavily artillery to detonate above ground, allowing a explosive power to exist as fully used against targets on the ground. A trenches of WWI, e.g., wouldn't use been efficacious protection against the bombardment applying proximity fuses.

Any of a above threesome technologies would keep around rendered the crossfire useless. Modern warfcome hwhen non returned to large impedes of foot because a above inventions likewise stamp out collected foot swell, & by using a perfection of shoulder launched rockets & preciseness bombing, stationary targets are when well vulnerable to exist as as fatal as a crossfire was around WWI.