The first strategic ballistic missile was the German V-2, developed during World War II.
It had a range of 320 kilometers, enough to hit a neighboring country, but no further.
During the Cold War rockets became steadily more powerful, capable of achieving greater ranges.
The first ICBM was the Soviet R-7, successfully launched in 1957 CE.
It was powered by a two-stage rocket and had a range of 8,800 kilometers, sufficient to cross an ocean.
Its accuracy was limited to several kilometers, precise enough to hit a city but not a military base.
Early ICBMs were notoriously unreliable, frequently crashing or exploding, yet engineers kept steadily improving them.
They had to compete with cruise missiles and at first proved superior in speed, range and accuracy.
Cruise missiles later surpassed them in accuracy, though ballistic missiles retained the advantages of speed and range.
As the last stage of the trajectory of ballistic missiles is effectively a free fall with very limited possibilities for course corrections,
their accuracy remains limited even in modern models.
The space race between the USSR and the USA was an important boost to ICBMs, as rocket technology had both civilian and military uses.
Early ICBMs used liquid fuels that had to be cooled and kept separate to just before launch, the mix being dangerous to the launching crew.
Later models stored the different liquids inside the rocket in different compartments, allowing for faster launches.
In 1962 CE the USA introduced the Minuteman I, which used solid propellants.
This made it smaller, lighter and safer than its predecessors.
Today all ICBMs use solid propellants.
The first ICBMs were launched from above ground, but as this makes them vulnerable to a 'first strike' by the enemy, were soon put in underground silos.
Later the introduction of mobile launching trucks and submarines brought them back above ground again.
The latter are often called Submarine-Launched Ballistic Missiles (SLBM).
In 1970 CE the USA introduced the Minuteman III, the first ICBM equipped with multiple warheads, called Multiple Independently targetable Reentry Vehicles (MIRVs).
This allows a single ICBM to hit multiple targets, up to thousands of kilometers away from each other.
The USSR soon followed suit with the R-36.
The R-36M remains the heaviest ICBM in the world, ranging as far as 16,000 kilometers with an accuracy of about 1 kilometer.
It can be equipped with 10 MIRV warheads, each yielding 550 - 750 kilotons TNT explosive power, or a single one of 20 - 25 megatons.
The nuclear arms race, which focused on ICBMs, swung back and forth between rapid armament and consolidation.
For a while both the USA and USSR developed Anti-Ballistic Missiles (ABMs),
but later scaled down these efforts as no defense system was able to repel a large number of incoming attacking missiles.
After the introduction of the MIRV-capable ICBMs the number of operational warheads increased.
In 1972 the USA and USSR signed the SALT treaty, which put limits on the number of ICBMs.
However it was annulled by the USA in 1986 CE.
That country then started to work on its Strategic Defence Initiative (SDI), which envisioned a defense network of lasers and particle beams to shoot down ICBMs.
When the Cold War ended, SDI fizzled out, though the USA later renamed and partially revived the program.
The START I (1991 CE) and START II (1993 CE) treaties again decreased the number of ICBMs, though the most powerful countries still retain several hundred.
Today only five countries produce ICBMs.
A few more have access to 'theater' ballistic missiles
that have intermediate range (3,000 - 5,5000 kilometers), medium range (1,000 - 3,000 kilometers) and short range (less than 1,000 kilometers).
These kinds of rockets are slower than ICBMs, but still faster than cruise missiles, though less accurate.
Almost all are capable of carrying explosive, chemical and nuclear warheads.
Their inaccuracy makes them suitable only for nuclear warheads, but this has not stopped several countries from using them in conventional warfare, despite the extensive colletaral damage.
War Matrix - ICBM
Cold War 1945 CE - 1991 CE, Weapons and technology