Eight nation-nodes orbit a shared "global pool" core. A cross-border crisis (stand-in for climate change or a pandemic) grows on its own each tick; it only shrinks when nations route resources into the pool. Each nation has its own baseline cooperativeness, but the Sovereignty ↔ Cooperation slider is the collective-action dial: pushed toward sovereignty, every nation discounts the shared benefit and keeps more for itself — the textbook free-rider problem, since the crisis-reduction a nation buys is non-excludable (everyone benefits whether they paid in or not).
crisis += severity · dt // grows on its own
contribution_i = coop_i · (1 − sovereignty) + noise_i
capacity = mean(contribution_i) · (veto ? 0.25 : 1)
crisis -= capacity · dt
The Cast Veto button models a UN Security Council-style veto: one permanent-member node turns gold and blocks ~75% of the pooled response, even if every other nation is fully cooperating — a single objection can paralyze a coalition built by consensus. Particle pulses along each spoke show resources actually flowing toward the core (green, high contribution) or stalling (red, free-riding); the ring around the core reddens as the crisis level climbs.
- Sovereignty ↔ Cooperation — the core trade-off: retaining national control vs. ceding capacity to a collective response.
- Crisis severity — how urgent and fast-moving the shared problem is; a slow crisis tolerates more free-riding than a fast one.
- Cast Veto — toggles a single blocking power, illustrating why UN Security Council reform (the "G4" proposal) keeps coming up.
Real-world relevance: this is the structural tension in every account of global governance — from Bretton Woods quota votes to the Paris Agreement's non-binding pledges — coordination gains are real, but sovereignty costs and veto points routinely keep response capacity below what the threat requires.