Your WMD arsenal can be programmed to respond quickly. So, it's good to get ahold of one of those for deterrence purposes. A sneak attack will quickly lose momentum however, between defender bonuses and the fact an occupier needs one army AND one victory for each province.
As a further advantage for the defender, armies recruited don't become active until the following turn. So, it all adds up that the defender has plenty going for them.
A 50-province country being sneak attacked by a 10-army invader only has to worry at most about 10 provinces lost, even if they only had one army. On top of that, the defender always has a 1/5 chance of winning. And, they will have forewarning that the attacker's army is building up as time goes on, and should in turn prepare their own deterrents - their own army, a WMD arsenal, or a coalition of possible allies.
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I was bored, so. Since Yoshiegg never really touched upon Demonkind:
An Analysis of the Post-Orobourite Race
Circa 2100, a serious anomoly in the world's genetic codes had finally culminated in the birth of a seemingly otherworldly race, colloquially referred to as "Demons," even by themselves. The title went a great way to inspire fear (and hate), but as a technologically-strong nation, the Demons did not mind such isolation. It meant they could focus on building better and more efficient technology.
The term "Demon" became a catch-all for anyone of origin from the realm, even humans. Those who were ethnically Demon, however, were the real targets of such a term. The term was not entirely unfair; those of the race possessed superhuman abilities, and often lacked a human appearance. Furthermore, there were many supremacists amongst the ranks of Demonkind, eager to expand territory, though infighting often prevented much success in this regard. Humanoid, furry or just bizarre, the Demons have historically served under a variety of leaders - Laharl, Iblis, Orobouros, Demise, Naraku, to name a few.
Later in the century, tumultous leadership resulted, with their humanoid Demon King being replaced by
one of his Demon Lords, the fiery, infernal creature who called himself "Iblis." This sociopathic monster led the realm for several years, steadily enlarging the state's WMD arsenal, ignoring fission and fusion in favor of chemical weaponry. This fed the Demon Lord's own personal sadism as much as his own disdain for nuclear weapons. It would not be until later when the reasoning behind this disdain became apparent.
At some point or another, Iblis fell. In a bizarre show of demonic qualities, his mind seemed to be completely altered, nuclear energies (based on records) having brought out a kind, pacifistic side. All the chemicals that had been so steadily built up were used for peaceful purposes, and the damaged records show that he apparently found a way to refine the "Chaos energy" of his people, the backbone of much Demon power, into something far greater. It seemed the Demon Lord himself was made of this energy, as a degraded video of the time shows him drawing it from his arm as if it was his blood.
While the data is sketchy, it is not unreasonable to assume the "Chaos fusion" energy, virtually limitless, able to match if not outpace nuclear fusion, was a dominant power source for the better part of two centuries. The legacy of this energy's abilities are still felt in the large airships that nations now sport, enabling nations to swiftly rearm and repurpose their armed forces at minimal cost. The procedure to refine the energy seems to have been lost, but who is to say a second Orobouros shall not one day rediscover the lost art?
Since that time, the Demon Realm has fallen and faded away for some reason or another. A large diaspora has spread across the world, primarily in East Asia but across much of the world regardless. Many Demons now consider themselves nationals of their new homes rather than of the lost Kingdom, though there have been violent ethnic nationalism attempts in some countries based on records. The "Demons" have spread far and wide, going by many names, dividing into many categories, but their great talents have made them subjects of constant research and employment in scientific and security fields.
Various other terms used to describe them: Orobourites, Orobi, Kaetif, Oni, Yokai