A simple mechanism to fence in cattle turned into one of the most inhuman weapons in the World War I. Armies put up barbed wires along the trenches and clearings and chased enemies into them, either by firing from all sides or smoking them out. The hapless soldiers ran into the wires and were pinned down by the barbs. Very few of them escaped. Those who survived the barbs were promptly gunned down from the trenches. The barbed wires have stayed on as a torture device, particularly in jails and in mental asylums until the 1960s.

The razor wire is now used along international borders and other strategic locations. Razor wires were first used to guard prisons and mental asylums in 1960s. Today, many countries use laser walls to protect their boundaries. Government of India has also started using the laser walls to guard the line of control.

The gigantic airships that drifted over the heads of enemies and bombarded them were named after their inventor, Count von Zeppelin, a German soldier. Germany used them in the early years of the war. They were even fitted with machine guns. Zeppelins rose on gases such as hydrogen. They caused untold misery to the British side. They could travel 85 miles per hour and could carry bombs of two tons. They were susceptible to firing and soon withdrawn from service. Zeppelins bombarded 51 places, killing 557 people and injuring 1,358 people. As many as 5,806 bombs were showered from Zeppelins. However, Russia's 'Ilya Muromets' is the most feared fighter of its time. The four-engine bomber could fly long distances and carry bombs of up to 500 kg and drop them over targets 600 km away. The Germans fighters were no match for 'Ilya'.

Tupolev Tu-160 is one of the Soviet-era bombers that have survived the military budget cuts after the end of the Cold War. Russia also relies on the Tu-22 M3 and Tu-95, while the United States have B1, B2 and B52. These modern fighters no longer carry bombs. They are armed with cruise missiles that can travel for thousands of kilometres. The supersonic Tu-160 is the fastest bomber in the world now. It has been upgraded with electronic features since 2000.

During the World War, air raids were a common practice for all sides. The main objective was to cause massive destruction to the enemy country. Air raids were conducted in both military zones and cities. Areal or inert bombs were mainly used in such attacks. These bombs were dropped by hands from aircraft. There were many varieties of areal bombs. Back then, Germany, Briton and United States had dedicated squads for air raids.

The GBU-43/B Massive Ordnance Air Blast (MOAB), a large-yield bomb of the United States, is also known as the 'Mother of All Bombs.' It was developed by Albert L Weimorts, Jr, of the US Air Force Research Laboratory. It is said to be the most powerful non-nuclear weapon in the American arsenal. It is designed to be delivered by a C-130 Hercules. The first known combat use of the MOAB was reported during the US airstrike against the Islamic State of Iraq and the Levant (ISIS) in Khorasan Province tunnel complex in Achin District, Afghanistan.

MG 08 were the German version of the first automated machine guns to be developed by Hiram S Maxim in 1884. The generals saw that a single machine gun did the work of up to 200 rifles. About 21,000 British soldiers fell victim to the automated guns in the Battle of Somme on July 1, 1916. The guns were so successful that they made their appearance in the World War II as well. MG 08 was prone to heating up after several rounds of firing, making it necessary for gunners to carry a 3.7 litre jacket of chilled water to cover the barrel with. Some of the models could fire about 600 rounds per minute. The range was between 2,200 and 4,000 yards.

The hot favourite of the US army is known for its user friendliness and devastating effects. Officially called M249 Squad Automatic Weapon (SAW), it's popularly known as SAW. It is 41 inches long and weighs 7.5 kg. It has a range of 3,600 m. It can fire 725-1,000 rounds per minute. It has a cooling mechanism and its barrel can be changed quickly.

At least 3,000 chemicals had been tried out to aggravate the devastation on the war fronts. About 50 of them found their way to the battle fields. The most fatal of them were chloramine and mustard gas. Chlorarmine was known as a 'vomiting agent' and 'sneezing gas'. The chemical weapon was harsh on the lungs, for a short time. The plan was to immobilise the enemy line for a while. Germany used mustard gas (sulphur mustard) for the first time in 1917. The Allied Powers called it the 'hot stuff', or simply 'H'. They could singe skin and lungs with devastating effects. They were recognised by their peculiar smell. Ordinary gas masks provided no protection against mustard gas. The poisonous gas killed about 4,000 British soldiers and injured about 1.6 lakh. Many people lost eyesight after being exposed to the gas. The French had an equally potent chemical agent – phosgene. The symptoms would not appear for two days after exposure. By then fluids would start accumulating in the lungs, leading to certain death. Phosgene contributed to 85 per cent of war-time deaths due to chemical agents.

The international community has banned the use of chemical weapons but deadly agents such as sarin were found to have been used in Syria recently. Sarin is a “nerve agent” that affects the neural system. The colourless odourless gas can immobilise lungs within a few minutes. Death is certain if inhaled.

A torpedo attack drew the United States into the World War I. A German U-boat sank British liner RMS 'Lusitania' in May 1915. The 1,195 victims included 128 US citizens. The US declared war on Germany. The German torpedoes targeted the commercial fleet that supplied wartime Britain. Torpedoes could be launched from U-boats, ships and boats. A version of torpedoes that could be launched from aircraft was introduced in the World War II. Self-propelled torpedoes were 19-21 feet long. The boats that carried the torpedoes were faster. They carried just two to four torpedoes but they were enough to sink a ship.

Black Shark Advanced (BSA) is a torpedo that can strike targets on land and at sea. They can be deployed from ships or submarines. They carry fatal doses of explosives. They could identify targets from even 50 km away. The electrical propulsion system operates on battery. It has sensors to identify targets and a digital feature to analyse data.

Mortars were versatile weapons because they could be carried around by soldiers. They could be used on enemies even while hiding in a trench, making the attacker less susceptible to attack. The guns were lighter too. Britain's mortars could fire 22 shells of 3 inches per minute. They flew up to 1,200 yards before exploding.

Mortars have tremendous striking capacity these days. The 81 mm L16 mortar is operated by three soldiers. The weapon jointly developed by the United States and Canada can carry shells weighing 4.2 kg across 5,000 m. They deploy the shells with the help of GPS navigation. It can fire 15 rounds per minute. Mortars come bigger and better. Some of them can be transported on vehicles. Some of them can even target submarines.

The first drafts of drones appeared as early as the World War I. The U.S. Navy built the drone in 1916-17 and named it Kettering Bug after the inventor, Charles Kettering. This was designed as a flying bomb, a precursor to cruise missiles. It was 18.5 foot long and weighed 175 pounds. It could project itself to the target by fixing the trajectory with the help of a gyroscope and barometre. It could strike a target which was 121 km from the launch point. It had a speed of 80 kmph. The first experiment towards the end of the war was a failure though.

The 21th century belongs to unmanned compact aerial vehicles (UCAV), popularly known as drones. They can be used for surveillance and warfare. Their biggest attraction is that they are expendable. The remotely operated drones can go anywhere without fear of loss of life. Some drones can carry missiles and bombs for several kilometres. The MQ9 'Reaper' from the United States can fly for 30 hours non-stop. The capacity would be reduced to 23 km, if carrying weapons. They can cover 1,850 km at an elevation of 50,000 feet. The United States have launched special ships for drones to take off and land.

Sqadron commander Edwin Dunning created history when he landed an aircraft on HMS 'Furious' on August 2, 1917. The 786-foot-long US ship had two big guns but they were too strong to shake the ship when fired. The design flaw left the admirals with no option but to use the ship as an aircraft carrier. The aircraft were taxied into the hangars below the runway. The same design is seen in modern aircraft carriers.

The United States built the largest aircraft career in the world in 2017. It will be commissioned in 2022. The 1,106-foot long ship can carry more than 75 aircraft including F 35C and about 4,539 personnel. It has sophisticated weaponry including missiles and laser. The traditional steam-powered launch system has been replaced by electromagnetic aircraft launching system. Two A1B nuclear reactors power propulsion. It also has zonal electrical power distribution system, allowing more than 25 per cent extra electrical capacity thanthe supercarrier USS 'Nimitz'.