Stasis is the quickest way to be 'sustainible' but is a far from ideal outcome. Even if we ignore the squandered potential, take a look at what happened to Japan and others who pursued policies of stagnation for the sake of stability. The lucky ones only got admiral Perry-ied. The unlucky ones were brutally colonized or conquered. The really unlucky ones no longer exist.

States are what can be called superorganisms literally made entirely out of coercion to get others to serve their goals without their consent. Despite the claims of social contract, nobody ever signed one. Asking statew not to seek dominance is like asking a wolf to take up vegetarianism. They technically could do it but it goes fundamentally against its entire design and purpose.

Not to mention that saying no to 'more' isn't kumbaya everyone has peace and freedom. It means active suppression of ambitions of others. States are made of coercion, remember?