Here is a concise summary of the provided text:
**Title:** Evolution of Anti-Tank Warfare: From Shaped Charges to Active Protection Systems
**Summary:**
* Anti-tank warfare has evolved from kinetic energy-based projectiles to shaped charges, which create a hypersonic jet of metal to penetrate armor.
* Shaped charges, used in RPGs, have limitations: their effectiveness decreases with distance, and a small gap can reduce their impact.
* Countermeasures include:
1. Metal cages (to cause premature explosion)
2. Explosive Reactive Armor (ERA) with insensitive explosives, which detonate only from powerful shockwaves.
* However, modern anti-tank weapons (e.g., Javelin) with tandem warheads can overcome ERA.
* The future of tank protection may lie in Active Protection Systems (APS), which can detect and neutralize incoming threats.
* The cost-effectiveness of tanks ($5-10M + APS) is being challenged by the relatively low cost of anti-tank missiles (e.g., Javelin, <$200,000), potentially shifting the balance from tanks to infantry.
Here are the extracted key facts, each with a number and in short sentences, excluding opinions:
**Historical Facts**
1. Tanks first appeared in World War I (WWI).
2. Early anti-tank rifles relied on kinetic energy of metal shells to pierce armor (WWI).
3. Soviets developed the RPG-43, a hand-held anti-tank grenade, during WWII.
4. The RPG acronym originally stands for "Ручной Противотанковый Гранатомёт" (Handheld Anti-Tank Grenade Launcher).
5. The Soviet RPG-7 was developed to launch anti-tank grenades from a distance.
**Technical Facts**
6. Anti-tank rockets can move faster than the speed of sound.
7. Shaped charges create a focused jet of metal particles that penetrate armor at hypersonic speeds.
8. The kinetic energy of the jet, not the shockwave, penetrates the armor.
9. The effective penetration depth of the jet is 7 times or more the diameter of the shaped charge.
10. Explosive Reactive Armor (ERA) is designed to counter anti-tank weapons.
**ERA and Explosives Facts**
11. ERA contains insensitive explosives that detonate only from extremely powerful shockwaves.
12. C-4 is an example of insensitive explosives used in some ERAs.
13. Insensitive High Explosives (IHE) were developed to withstand forces up to 1,500 feet per second (for nuclear weapons).
14. Conventional high explosives detonate at impacts as low as 100 feet per second.
**Modern Warfare and Technology Facts**
15. Modern anti-tank weapons (e.g., Javelins) have tandem warheads to neutralize reactive armor before delivering lethal damage.
16. Active protection systems (e.g., hard-kill systems) are being developed to detect and neutralize incoming threats.
17. The cost of a tank (excluding active protection system) is $5-10 million, while a Javelin round costs less than $200,000.
**Incident Facts**
18. Nuclear-armed B-52 bombers crashed in Palomares (1966) and Thule Air Base (1968), prompting the development of more stable explosives.
19. During the 2017 Marawi siege (Philippines), militants used RPG-2s, and government forces improvised with wood and cardboard to reduce the effectiveness of the RPGs.