Trope:Awakening the Sleeping Giant

"I fear that all we have done is to awaken a sleeping giant and fill him with a terrible resolve." — Attributed to Naval Marshal General Isoroku Yamamoto, after the attack on Pearl Harbor

Everyone knows about the Big Good and the Big Bad, but what about the Even Bigger Neutral?

In most conflicts, there are a variety of neutral parties. From the Precursors to the Retired Badass to the King in the Mountain to the Hidden Elf Village, they always exist and there's usually one that cankick the shit out of both the other sides at the same time, using only a kitchen whisk and a sheet of tissue paper. The thing is... they're not involved so don't ask them for help because they will refuse to get involved.

That is, unless someone does something stupid or evil enough to repulse them. Whether it was the heroes or the villains, anyone who steps over some inexcusable line will invite their wrath, and this isn't the regular Neutral No Longer give-the-other-side-some-reinforcements wrath ... this is "we have an army of Cthulhu clones" wrath. Expect an Oh Crap from the receiving end if and when the former neutrals start whipping out the doomsday weapons. On the other hand, for the beleaguered side not subject to the proverbial giant's wrath, this is a moment of celebration as they gain a powerful ally and they will fight alone no more.

There are two key points to look for before and after this trope comes into play.

Before: There is an established conflict, of any sort, between any number of parties, with a prominent neutral party that wishes to remain uninvolved. After: When the neutral party enters the conflict, it drastically alters the balance of power.

A Sub-Trope of Neutral No Longer and related to Heroic Neutral. May serve as a Deus ex Machina and/or Story Breaker Power (and/or Game Breaker, if the work is a game) if the giant was an All-Powerful Bystander. Compare Default To Good. If the entity is an individual, then they won the Superpower Lottery, and it's likely they are a Martial Pacifist.

Examples

 * The New Aurelian Army was waging an war for the throne of Aurelia with the Imperial Republic of Aurelia. The war was going poorly and in a crowning moment of stupid the NAA attacked Directian forces that were moving through the region. Directus, the largest military power in the world (being atleast twice as powefull as the next strongest nation) responded by crushing the NAA's entire military force and laying seige to its capital. In a month. With a single legion.
 * Both ISAF and to lesser extent Leasath have tried to avoid doing this to Directus in the War in the North. At various times Directus has been one Kick the Dog away from invading either or both nations, though thus far this has been avoided.