In short, the Planet Earth has become a giant fracking battlefield, or at least a significantly widespread number of sections of it have. The causes of war can range from countries engaging in a wide conflict to an Alien Invasion.
When Earth is subject to this trope, it's hard to find anywhere on the planet where there isn't violent fighting going on. Anywhere you do find that's peaceful now could easily become thick with fighting at a moment's notice, if it wasn't thick with fighting previously. Nobody on Earth is untouched by loss of loved ones.
Name is a pun on both the Pat Benatar song "Love Is a Battlefield" and Battlefield Earth, neither of which have anything to do with this trope.
Often involves Humans Are Warriors.
Examples:
- Most Gundam series involve a world war that engulfs the Earth and the space colonies in the "Earth Sphere"—often using one "battlefield" as a weapon against the other. In particular, the rules for the Gundam Fight of G Gundam state that "Earth is the ring"... shown by the existence of laser boxing-ring ropes circling the planet, which a Gundam actually bounces off. Most of the well-off people live in space colonies. Mobile Suit Gundam: The Witch from Mercury has all of Earth engulfed in a Forever War engineered by the space colonists for their own profit.
- In the final episode of Jormungand, nearly every continent has descended into this. A "New USSR" and the United States are locked in a second Cold War, the Indo-Pakistan conflict has started anew, a sixth Arab–Israeli Conflict has erupted in the Middle East, China has suffered an economic crash, race riots are breaking out in Indonesia, drug cartels and left-wing terrorists have turned much of Latin America into a smoking wasteland, the same can be said of Africa as its many civil wars have escalated, and Europe is under siege by a massive new spate of terrorism to the point that Big Ben has been destroyed. The only continents that seem untouched are Antarctica and Oceania.
- Strike Witches has Japan, Germany, Finland, Russia, France, Italy, USA and the UK fighting an Alien Invasion at the same time. In panties.
- This trope is played straight in Super Dimension Fortress Macross/Robotech, in which all of Earth bombarded and devastated in a planet wide assault. Furthermore, this experience was the driving reason in the aborted sequel Robotech: The Sentinels for the heroes to lead a major armed expedition to the Robotech Masters' world. Ostensibly, the major goal is to come to an accord with that power, but if it comes to fighting, then at least their world will be the battlefield this time. The Macross continuity has humanity specifically anticipating this to happen again in the future and taking precautions.
- It happens in several Legion of Super-Heroes story arcs:
- In The Earthwar Saga, the Khunds invade Earth, forcing all Legionnaires out of retirement to fight them in every front.
- In The Dominator War, the Dominators have all but conquered Earth thanks to a worldwide machine-controlling techno-plague. In retaliation, the Legionnaires attack and conquer the Dominator homeworld.
- The Conversion Bureau: The Other Side of the Spectrum has the Eastern US coast (Boston in particular), Nairobi, New Dehli, and New Brunswick on the frontlines of a war against xenocidal aliens, while the rest of the world trapped in a life-destroying barrier.
- Coreline: When Dimensions Collide, the result is every bad guy in almost known work of fiction of humanity fighting against every good guy in almost every known work of fiction of humanity, with an awful lot of people stuck in the middle (and either self-enforcing "Took a Level in Badass" or die). This is a conflict that has gone through hot and cold cycles, with the "CHIMERA War" arc starting on Coreline Operation Snake Charmer and ending on Coreline Operation Endgame being the latest "hot" period.
- In the second act of Hellsister Trilogy, the whole world has been engulfed in war because of Darkseid's invading forces. The situation gets so bad that, while the New Gods and Justice League try hold Darkseid's army at bay, Supergirl and other heroes travel to parallel dimensions to ask for help and reinforcements.
- In Kimi No Na Iowa, Abyssals have attacked almost everywhere on Earth, although countries without major participation in World War II "only" got their ports and navies destroyed.
- Poké Wars shows Kanto, Johto, Hoenn, Sinnoh, Orre, Fiore, Oblivia, and Almia as war-torn hell holes.
- Regret: In the future, Kanto, Johto, Hoenn, Sinnoh and possibly Unova are torn apart by war and a highly contagious Hate Plague.
- Superman of 2499: The Great Confrontation is heading towards this, with the XXVth century descendants of the House of El fighting each other in a planetary-scale war.
- "Tarkin's Fist": The Empire-Earth war begins with an orbital bombardment of Earth's major cities and military installations. The war develops into a three front conflict. Front one consists of an invasion of the Western Coast of the United States, targeting Los Angeles before pushing inland towards Las Vegas. Front two consists of an invasion of China focusing on Shanghai and pushes as far as Wuhu by the Yangtze river. Both fronts serve to tie down the North American Union and the People's Republic of China and prevent them from intervening in the third theater of the war; an island hopping campaign across the Pacific islands designed to abduct as many people as possible for slave labor needed to develop the new Imperial economy on Mars.
- The majority of Warbound Widow is based on Earth as the inhabitants get in a worldwide war with the invading Alternian Empire. Name a country and it's under attack; it's so bad most of humanity has been forced to retreat underground because of the sheer number of battles being waged constantly upon the surface and have to use guerrilla warfare.
- Worldwar: War of Equals has the alien forces land in strategic positions around the world facing the best 21st century militaries can dish out. Unlike the situation in the source material, the world isn't wrapped up in World War II and even spotted them right outside our solar system almost two years ago, giving Humanity time to prepare itself.
- Psycho-Pass: The Movie tells us that the whole world is engulfed in war, except for Japan thanks to the Sibyl System's control.
- Avengers: Endgame: With the Avengers being down a member following Nat's Soul Stone sacrifice, Doctor Strange, Black Panther, Shuri, Okoye, Falcon, Wong, various sorcerers (Tina Minoru and Hamir included), Stakar Ogord and his Ravager clan consisting of Aleta Ogord, Krugarr, Martinex, and Charlie-27, Spider-Man, Mantis, Kraglin, Wasp, Korg, Miek, Scarlet Witch, Bucky Barnes, Groot, Valkyrie, and Howard the Duck among many others arrive on Earth to make sure the Avengers don't feel outnumbered in their fight against Thanos and his army.
- Battlefield Earth, albeit in the past tense (humanity was curb-stomped long before the plot gets going).
- Critters: Alien bounders wreck the countryside hunting the aliens, with humans caught in the crossfire.
- Godzilla: Final Wars: Giant monsters controlled by aliens destroying major landmarks while fighting Godzilla, anyone? Of course, Final Wars is essentially a remake of Destroy All Monsters, which basically has the same premise: aliens control giant monsters (including Godzilla himself, who attacks New York City) that destroy major cities.
- An interesting case in Hackers, as hackers from all over the world join in a virtual attack on the Gibson supercomputer in order to overload its defenses.
- Independence Day, even if it focuses on the United States.
- Terminator Salvation makes the trope particularly clear, with a radio message being received by sparse resistance fighters across the entire planet.
- The later books of the Animorphs series, after the morphing cube is stolen and Visser Three launches open war.
- Legacy of the Aldenata does this, with Posleen landings all over the place generally making life rather suck for most humans.
- The War Against the Chtorr, and humanity is losing.
- The appropriately named Worldwar series has alien landings in sites across the world in the middle of 1942. It's debatable whether this trope applies after the first three months of war: during that time the alien Race conquer and subdue most nations apart from the great powers who were mobilized to fight World War II. However, partisan resistance continues everywhere, the area Turtledove mostly writing about being China.
- In BattleTech, Terra, while normally a very stable location, has been site to some of the largest and most horrific battles in the Inner Sphere courtesy of the Sol system being the most developed system in known space. The Amaris Civil War resulted in the largest space battle ever recorded and a two year campaign on the surface to take out Amaris the Usurper, in a war that would kill millions. The Word of Blake Jihad caused two separate wars, and the last of which had the Word of Blake use nuclear, biological, chemical, and orbital weaponry.
- In Teenage Mutant Ninja Turtles & Other Strangeness, this was what much of the Earth's future looked like: evacuated by all organic life and used as a killing zone by psychotic A.I.s hiding in underground bunkers.
- Warhammer 40,000 has a whole galaxy in constant war. Earth itself, on the other hand is relatively safe by Warhammer 40K standards, though back in the Age of Strife, around ten thousand years ago, it was divided into warring techno-barbarian empires that only stopped when the Emperor arrived to conquer it all and stop the fighting.
- The Command & Conquer series. The Tiberium series and Generals were global from the beginning. The Red Alert series was confined to Europe in the first game but quickly went global in its latter two installments. Most of the fighting in the Generals series happens in China, the Middle East, and Central Asia. The Zero Hour expansion pack takes this further: the United States has a mission in Somalia, the GLA visits the continental US to steal their newest weapon and then attacks Greece & Germany, while four-fifths of the Chinese campaign happens in Germany (the other one-fifth occurs in western China, probably the Xinjiang region).
- Final Fantasy IX: Once the player finishes the events in Terra. Kuja plans on waging war back on Gaia. Which the mist that used to only cover a bit of said continent has now covered the whole world. Making it hard to see what's in front of the player.
- Probably the Seven Hour War from the Half-Life 2 backstory, though it was more of a Curb-Stomp Battle. A more straightforward example is the uprising in the more recent games. It's humanity vs the Combine, and it's unlikely that the fighting is restricted to Eastern Europe only.
- Halo: In the beginning of Halo 2, the Covenant launch a small preliminary assault on Earth which turns out to have been by accident, as the invasion fleet wasn't actually expecting to find any humans. By the beginning of Halo 3, this has become a full-blown invasion, with cities all over the world overrun by the Covenant.
- Mass Effect 3 itself starts with the Reapers invading Earth. Over the course of the game, you hear from Anderson, who is leading a global resistance movement that's fighting back against the Reapers as best as they can, even when indoctrinated authority figures attempt to criminalize doing so. Then the final battle takes place in London, which looks rather like it's been hit with many, many hammers for a period of several weeks.
- The world has descended into something closely resembling this in the beginning of Metal Gear Solid 4: Guns of the Patriots. It's especially apparent in the fake ads that appear before the opening cutscene.
- Invoked in Shin Megami Tensei: Strange Journey, where the first sector of the Schwartzweld, Antlia, is modeled after a burning warzone. The reason? Its Tyrant, Morax, is the embodiment of humanity's warlike nature.
- The X-COM series is a prime example of this trope, where Earth is in the midst of a full-scale invasion of numerous alien species, so in essence, it seems that Earth has become China during the Mongol conquest.
- Xenonauts is a mild case, since the war is rather limited, but nevertheless any place on Earth may become a target at any time. It is an Alien Invasion game, after all.
- The world of the Civ Battle Royale is this by design, as the only enabled victory is Domination. By the end of Mk. 2, every single city on the map has changed hands at least once, most of them multiple times. The exceptions are several cities in Brazil, due to the fact that the Brazilians are the ones who finally do Take Over the World.
- The SCP Foundation features SCP-5000
, a mechanical suit the Foundation found which includes logs and files from an alternate reality where the Foundation declares a war of extermination on the rest of humanity for an unknown reason. In this alternate reality, using the anomalous items they collected, the Foundation started doing everything it could to kill as many people as possible all over the world, such as spreading memetic hazards on the internet, releasing infectious anomalies in large cities, triggering the eruption of Yellowstone, and even releasing/resurrecting hostile deities.
- In the American Dad! non-canon Christmas Episode "Rapture's Delight", the Rapture comes, and half the Earth's population ascends into heaven while the rest are left behind as Jesus returns to battle The Antichrist. In seven years, the world becomes a wasteland in the war between the angelic forces of Jesus and the demonic armies of the Antichrist. One battle is mentioned, the "Battle of Boca Raton".
- In the Grand Finale of Justice League Unlimited, "Destroyer", the entire League as well as the surviving remnants of the Legion of Doom team up and spread out across the entire world to battle the Forces of Apokolips, led by Darkseid.
- The Great Offscreen War in Steven Universe was a multi-century gem civil war between the ones who wanted to continue or stop colonizing Earth. The total area of where they fought does not appear particularly large, but gems' Portal Network and other transport methods lead to fights all over the planet.
- In most Transformers incarnations, the Autobots and Decepticons take their fights to Earth, usually to grab whatever MacGuffin happens to be there.
- The Ur-Example is actually the "Seven Years' War" in the mid-18th century, which had a bunch of simultaneous conflicts sprouting up over various points in the world. The part in North America is known as the "French and Indian War". Winston Churchill himself nicknamed it "The first world war".
- The Napoleonic Wars, although the main action was in Europe, also saw fighting in North America (in the form of the War of 1812), the Caribbean (in the form both of naval action and slave revolts, most especially the Haitian Revolution), Spanish America (with the wars of independence there being directly triggered by the occupation of Spain by France as the colonists fought about which of the rival claimants to the Spanish throne to back, what it meant to back which claimant, and whether it made any sense to back any of the claimants at all), the Middle East (on account of Napoleon's expedition to Egypt and the years of fighting that caused), sub-Saharan Africa (with the British taking the Cape Colony from the Netherlands after that country was conquered by France), and India (with the British seizing French outposts there, as well as some unrelated and/or opportunistic conflicts between the British and local rulers).
- This was a major element of British Empire strategy. Because of the British Empire's world-spanning reach and superior logistics, they could fund continental allies against any European power, while seizing control of trade routes and colonies everywhere else in the world and fighting many wars with heavy use of native auxiliaries. They benefitted from being able to fight in any theatre of the global battlefield.
- World War I, though mostly confined to Europe, saw fighting scattered throughout Africa and the Middle East, and at least one major engagement in the Pacific. Nearly every state on Earth was involved either directly or indirectly.
- World War II is a more direct example, as there was a lot of fighting all around Earth, in Africa, around North America, in Europe, in East Asia and the Pacific regions. Also small naval battles around South America.
- This map
shows all the armed conflicts going on in the present day. It's just showing the countries with active battlefields rather than every country involved—if it did, NATO and Australia would be colored in too.
- In a way, this has been true ever since the beginning of life on Earth. Not every square inch of terrain was at war all at the same time, but every living being has competed and fought against each other and the forces of nature for the right to survive and reproduce, from then to this present day.