Dogs have been by man's side for tens of thousands of years, aiding in hunting, herding and protection.
More recently, dogs have been used as war animals, providing support to soldiers on the front line.
Today, military working dogs (MWDs) continue to serve in various roles including explosive detection, patrolling and search and rescue.
They are highly trained and skilled at their jobs, often risking their lives to keep us safe. MWDs are true heroes and their contribution to the military is invaluable.
Purpose of military working dogs
Military working dogs (MWDs) are military personnel employed to serve military and police forces in various roles, such as explosive ordnance disposal (EOD), tracking enemies on the battlefield and attacking enemy soldiers.
Military working dogs - guardians of the night
Military working dogs are also known as the guardians of the night - helping military personnel to detect and respond to threats, both at night and during the day.
In active warzones, these military working dogs patrol the roads and streets with their handlers - often at night because these dogs can sniff out possible threats hiding in the bushes.

History of military working dogs
Their histories stretch back thousands of years - the earliest known use of these dogs is in the mid-seventh century BC, used by the Ephesians against Magnesia on the Maeander [1].
In more modern history, in 2011, a military working dog named Cairo, attached to the United States Navy SEAL team, was instrumental in the killing of Osama Bin Laden [source]
Role of military working dogs
It depends on the location that they're placed in.
Military working dogs in battlefields
For the dogs placed in active battlefield roles (Afghanistan, Iraq, etc.):
Their roles mostly revolve as military security guards at the bases, as well as helping military forces locate explosives.
Military working dogs help military forces secure military bases and key strategic points against counterattacks, too.
In general today, military dogs on active battlefields will are not used as forward attack dogs, unless a capture is needed, and it's safe enough.
For example, the military forces need to capture a single target in a building, and there's only one person in the building.
Other roles they serve are as search and rescue dogs, especially among the rubble in a destroyed building.
Domestic military working dogs (k9 dogs)
For their roles in the police force or domestic roles, their roles are far more apparent.
They are used far more often to apprehend suspects (biting and subduing) and helping to detain police suspects.
These military dogs are also used for drug busts - certain breeds, such as the Beagle or Bloodhound, have excellent noses that help law enforcement find these drugs or poisons on the streets.
They're also often used in airports to sniff for threats, such as bombs or any drugs.
However, these are usually considered as police dogs instead of military working dogs, since their roles are not considered military.

Requirements of military dogs
Depending on their role, they will need these traits below.
Attack dog
The dogs must be naturally aggressive - preferably naturally aggressive toward human targets.
They must show focus and desire to bite, hard, on command. Most of the time, their bite is so painful that most suspect would prefer to surrender than to continue the pain of getting bitten.
This is the reason why most attack dogs are German Shepherds and Belgian Malinois breeds - they are fast, have great endurance, and are very willing to take someone down if commanded to.
Trackers, or search and rescue military dogs
The dog's nose has to be able to detect target odors such as bomb materials, which can potentially prevent casualties in the event of IEDs (Improvised Explosive Devices) nearby.
Apart from that, they also need to be able to sniff out hidden caches as well.
Of course, for search and rescue dogs, they must be able to latch on to a faint scent of humans well enough to be able to find them through rubble, or hidden areas.
This is especially so when tracking suspects, or pulling fellow soldiers out of the rubble of fallen buildings.
Or, when trying to rescue kidnapped individuals when they are hidden so well that we can't find them.
These kinds of jobs require a high level of fitness from military working dogs, and tracking through rough terrain for long periods of time requires extremely good endurance from the,.
How military dogs are trained
The first thing to note is that military dog training is extremely difficult.
It takes twice as long to train military working dogs than it does for normal domestic police dogs, because the military has stricter requirements that must be met before allowing the dogs to work with military forces.
Also, military working dogs are typically trained by military forces or hired civilian trainers, who specialize in military dog training.
As much as we want to tell you,
However, what we do know about their methods is that training military working dogs is typically done using positive reinforcement methods.
This usually follows scientifically proven animal learning theory, on the quickest way to get them fully trained and ready for service.
As a side note, military dogs outrank their handlers so that they cannot be 'abused' by their handlers, though it's often more to do with military custom and tradition as well. (source)

Military dog qualifications
Most of the time, military working dogs are bred specifically for military service, and so they will (almost) always pass the military dog qualifications.
This is because military breeds typically have the traits that military forces want - healthy, fast, intelligent, able to handle difficult terrain and long hours of work with military forces.
As explained earlier, these traits are far more common in working breeds like German Shepherds and Belgian Malinois - which is the reason why many of them are also bred to specifically be military working dogs.
So, it's pretty hard to have a random dog on the street or in a home and put it through rigorous training and obtain military dog qualifications.
Of course for the less aggressive roles like the tracker or search and rescue, any dog that shows the capability of being great at those roles can be considered as well - for example, it's not uncommon to see Labrador retrievers or beagles as trackers in the military.

Conclusion
Military working dogs are an integral part of any military or fighting force, and they serve a number of purposes.
They help soldiers with tasks such as sniffing out explosives or locating missing persons, but these four-legged members also provide emotional support to the people that work alongside them.
If you want to learn more about how your dog can be trained for service in law enforcement or special operations, contact your local armed forces branch!
In the meantime, you can all about positive reinforcement training techniques so you can start getting your dog ready for duty tomorrow.
References:
[1]: P.A.L. Greenhalgh, Early Greek Warfare: Horsemen and Chariots in the Homeric and Archaic Ages (Cambridge University Press, 1973, 2010), p. 145.