Air Force
Although armies and navies have been fighting for thousands of years, air forces are fairly recent. An air force needs airplanes, and the airplane was only invented in 1903. The airplane soon became an important weapon of war.
Planes equipped with machine guns shot one another out of the sky for the first time during World War I (1914-1918). Pilots sometimes tossed hand grenades (small bombs) from the cockpit onto enemy troops on the ground.
Today, most nations have an air force for their defense. An air force protects a country from attack by air. It uses radar and airplanes to detect enemy aircraft. Fighter planes and missiles then intercept and destroy enemy airplanes.
Air forces can also attack. Bomber planes drop bombs on enemy territory. Bombers try to knock out targets on the ground and prevent the movement of troops and supplies. Fighter planes conduct combat in the air with enemy aircraft. Missiles carry explosive weapons that attack targets in enemy territory.
The air force plans and carries out military operations along with the army and the navy. Another job of the air force is to transport troops and supplies.
People began to think about the military possibilities of airplanes soon after the airplane was invented. After World War I, some military experts thought the next war would be decided by air power. Others disagreed.
Air power played a major role in World War II (1939-1945). Germany’s Luftwaffe (air force) tried and failed to defeat Britain’s Royal Air Force in the Battle of Britain in 1940. Airplanes that were based on aircraft carriers at sea carried out bombing raids on the enemy. Although bombing did not decide the outcome of World War II, it played an important role in the defeat of Germany and Japan.
In 1947, after the war ended, the United States government created an independent U.S. Air Force. Until then, the air force had been a branch of the U.S. Army. Today, the United States has the strongest air force in the world.

Have you ever wanted to look out over the ocean from the deck of an enormous ship? Or maybe you’ve dreamed of traveling in a submarine deep beneath the water. Sailors in a navy do these things every day.
A navy is part of a country’s military force. Navies are military forces on, under, and over the sea. They are made up of ships, submarines, airplanes, and sailors. Navies protect their country’s ships and shores. In war, navies attack enemy coasts and ships.
Navies have been around for a long time. Ancient countries such as Egypt, Phoenicia, Greece, and Rome fought naval battles in the Mediterranean Sea. Naval ships of the ancient world, called galleys, had sails that caught the wind in order to sail. They also had men rowing with oars. In battle, ships tried to ram one another. Archers fired arrows into enemy ships. Soldiers on board swarmed onto enemy vessels to fight.
By the 15th century, wooden ships had grown larger. New instruments such as compasses helped sailors navigate, or guide, their ships. Ships began to carry cannons to shoot at other ships.
The Industrial Revolution in the late 1800s again transformed naval ships. Steam engines replaced sails and allowed ships to go faster. Ships began to be made from iron, and later steel, instead of wood. Guns capable of shooting longer distances replaced cannons. New inventions like torpedoes and submarines carried warfare beneath the sea.
During World War II (1939-1945) aircraft carriers became the main naval weapon. These huge ships carried planes that swooshed off the decks and bombed enemy ships. Hidden submarines played a large role in sinking trade and warships. Radar helped find enemy ships and planes.
Today, some submarines and large navy ships are powered by nuclear energy. Submarines use nuclear power so they don’t have to carry a lot of fuel and can stay underwater longer. Big ships such as aircraft carriers use nuclear power so they can go faster and travel greater distances without refueling. Modern ships also use very accurate missiles. Computers tell the sailors exactly where the ship is and warn them when other ships and planes are nearby.

What do knights wearing shining armor, archers carrying longbows, men marching in orderly lines, cannons, guns, and bombs have in common? They’re all developments that improved armies. Armies have been around for thousands of years.
An army is the portion of a country’s armed forces that fights on land. (The navy fights at sea, and the air force fights in the air.) An army includes soldiers, weapons, and other equipment. It also includes a support system set up to provide soldiers with transportation, supplies, medical care, and information about the enemy.
Armies defend countries against invasion. They can also invade other countries or occupy other countries to keep the peace.
Armies do more than just fight wars. They also help out during natural disasters, such as hurricanes and floods. Sometimes they build roads, railways, and bridges. They can also help keep the peace inside their own countries during riots and other unrest.
In ancient times many soldiers were untrained volunteers who had to supply their own weapons and equipment. Modern armies pay, train, and equip their soldiers. Countries sometimes draft soldiers, especially during big wars or when they’re being invaded. Drafted soldiers don’t have a choice—they have to serve in the army.
Soldiers tend to be young, in their late teens or early twenties. They have to be healthy and able to run fast and carry heavy loads. Soldiers have generally been men throughout history. During the 20th century many countries began to allow women to be soldiers. Officers in armies command groups of soldiers.
Soldiers need lots of equipment to fight and protect themselves. In the past that meant swords, armor, horses, or bows. Today it means guns, uniforms, vehicles, tanks, bombs, and even computers.
In modern armies, soldiers wear bulletproof clothing and use guns with laser aiming devices that tell them exactly where they’ll hit. They consult computers that show what the surrounding land is like and where enemy troops are. Huge planes carry troops and even tanks from place to place.

They enforce laws and maintain order. They investigate crimes and patrol neighborhoods to keep them safe. When there is an accident on the highway, they offer assistance and take charge of the situation. If you get lost, they’ll give you directions. These are just some of the jobs police officers do every day.
Police work can be difficult and dangerous. But thanks to police officers, everyone lives more safely.
Policemen and policewomen are public servants. That means they are part of the government. In some towns, police chiefs are elected by local residents. In most big cities, the mayor appoints the police chief.
Every police officer is part of a police force. Different police forces are responsible for patrolling and protecting different areas. There are police forces in every country of the world.
In the United States, there are city, county, state, and national police forces. City police enforce laws within towns and cities. County forces patrol the areas outside of cities but within county lines. State police enforce state laws. National police, such as the Federal Bureau of Investigation (FBI), enforce national laws and investigate crimes that cross state lines.
Police perform many different jobs. Every day, police officers patrol streets to prevent crime and keep people safe. These police are called patrol officers. Patrol officers wear police uniforms and drive police cars. They might ride motorcycles, bicycles, horses, or patrol on foot. Patrol officers may arrest a person they see committing a crime.
Police teach people how to help prevent crime and to protect themselves. They rush to help people in emergencies, such as car accidents, flooding, and hurricanes. Police help find missing people and settle arguments between people. They watch for speeding drivers on the road and give traffic tickets.
Specially trained police investigate crimes that have already happened, such as robbery, kidnapping, or murder. These police are called detectives. Detectives look for fingerprints or other evidence at a crime scene. They ask a lot of questions as they gather information to try to solve a crime. Detectives usually wear plain clothes-that is, ordinary clothing instead of a uniform. That way, they can blend in while investigating crimes.
Police use radios, telephones, and walkie-talkies to keep in touch. Many police cars have computers inside them. If a police officer stops a car, the officer can check who the car belongs to by typing the license plate number into the computer. Computers help police across the country share information about criminals.
Most police officers carry a gun. They identify themselves by wearing or carrying police badges. Police might carry shields or wear helmets or bullet proof vests, depending on the dangers they face.
Some police departments use police dogs. Police dogs sniff out illegal drugs or bombs or they help find missing people.
Big cities usually have crime labs. Here, police scientists use special technology to help solve crimes. They examine weapons used in crimes for fingerprints. They analyze evidence, such as blood, hair samples, or clothing fibers from a crime scene. Their job is to use evidence to help find out who committed the crime.
If you ever watch television or go to the movies, you’ve probably seen the police in action. Many TV shows and movies portray the work of patrol officers, detectives, or crime labs. Some, like Hill Street Blues or NYPD Blue, present realistic portraits of police forces at work. Others, like C.S.I., give you a glimpse inside the workings of a crime lab.

Suddenly, across the green-foam waves a ship’s sail is sighted across the rolling waves. No country’s flag flaps atop the ship’s mast. Is this a pirate ship? The very word—Pirate!—stirs fear. Pirates are thieves. They swoop in blasting their cannons, fighting with swords and pistols. Pirates attack towns as well as ships.
Pirates are enemies of all countries. A pirate captain and his crew work outside the law. Any country may capture a pirate and put the culprit on trial for piracy.
Pirates have been a threat since ancient times. Pirates gathered wherever a country could not protect its trade ships.
Thousands of years ago, pirates sailed the Mediterranean Sea in search of valuable cargo. The ancient Romans spent an entire year sweeping the Mediterranean clean of pirates. In the 1000s, Viking raiders looted villages along the coast of Western Europe.
In the 1500s and 1600s, pirates called buccaneers attacked ships and towns in Spain’s colonies in the Americas. Buccaneers got their name from the French word for smoked meat. Buccaneers stole cattle, smoked the meat, and traded it for gunpowder, bullets, knives, and clothes.
Most buccaneers were English, Dutch, or French. Many were escaped criminals, runaway slaves, or adventurers. The tiny Caribbean island of Tortuga, near Haiti, served as the buccaneers’ headquarters and hideout.
From the 1600s into the early 1800s, pirates cruised northern Africa’s Barbary Coast. They attacked from the coastal cities of Algiers, Tunis, and Tripoli. The pirates demanded that a country pay them a ransom not to attack that country’s ships!
The United States also paid the Barbary pirates ransom. But eventually, President Thomas Jefferson sent U.S. Navy ships to the region. By 1815, the United States had forced many of the Barbary pirates to sign treaties or surrender.
In the past, when countries were at war they sometimes hired pirates to attack their enemies. These men were called privateers.
One of the most famous privateers was Sir Francis Drake, an Englishman. Drake attacked Spanish ships and towns in the 1500s. He returned to England with chests of treasure he divided among his investors. One of Drake’s investors was Elizabeth I, the queen of England.
Sir Henry Morgan, an Englishman, was a famous buccaneer in the Caribbean Sea. In the late 1600s, the English governor of Jamaica hired Morgan to fight the Spanish. Morgan attacked settlements in Cuba, Panama, and Venezuela. When England and Spain made peace, Morgan was captured and taken to England. But King Charles II of England believed Morgan was a loyal subject. He knighted Morgan and named him lieutenant governor of Jamaica!
The name Blackbeard was feared along the East Coast of the United States. An English pirate, Blackbeard’s real name was Edward Teach. Blackbeard wore his beard in braids tied with ribbons. He armed himself with a sharp cutlass (sword), daggers, and six loaded pistols. In 1718, Blackbeard blocked the port of Charleston, South Carolina. He seized ships and held passengers as hostages. British ships eventually tracked Blackbeard down and killed him in battle.
Anne Bonny and Mary Read were ruthless female pirates who sailed in the early 1700s. Both women dressed like men and fought in battles. Bonny and Read were captured together in 1720. Read died in prison. No one knows what happened to Bonny.
William Kidd was born in Scotland and raised in New York. Captain Kidd began as a privateer, but he soon went to work for himself. He attacked merchant ships off the coasts of India and Africa. Kidd was captured, tried in London, and hanged in 1701. Some of his buried treasure was later found on Gardiners Island, near the eastern end of Long Island, New York!
By the 1800s, pirates were having a harder time. Countries built better navies, and navy ships gained steam power, which made them faster. Countries made a point of hunting down pirates. But pirates, and piracy, still exist today. Armed robbers attack ships along coasts or at sea and steal their goods.