Geoeconomics Analysis · March 2026 · Analysis-005

H_{t+1} = H_t·(1 − ρ_I − n_t·ρ_S) Hegemony Decay & the Repeated Game

Each round of yuan-denominated Hormuz transit compounds the erosion of dollar hegemony. Iran's payoff is constant at G every round. U.S. payoff compounds downward. The trap tightens automatically without any strategy change — and the erosion does not reverse when the guns go quiet.

G ∀tIran's payoff every round
H→0U.S. hegemony over time
ρ_I+n·ρ_SDecay rate per round
∏ decayCumulative compounding
Explore the decay ↓

Equation 8

H_{t+1} = H_t · (1 − ρ_I − n_t · ρ_S) | U_I(t) = G ∀t
H_t
Hegemony at round t
The dollar's reserve-currency dominance at time t — the fraction of global energy invoiced in dollars, the depth of dollar liquidity, the credibility of dollar financial architecture. H_0 ≈ 1 at the start of the petrodollar era. Each round of yuan settlement erodes it.
ρ_I
Iran's decay contribution
The fraction of H eroded per round by Iran's yuan trades alone, regardless of other actors. Each Hormuz transit settled in yuan adds another CIPS transaction record, deepens the yuan payment rail, and sets a precedent for other importers. Estimated ρ_I ≈ 0.02–0.04 per round.
n_t·ρ_S
Swing state acceleration
n_t = number of Swing Producers who have switched to yuan by round t. ρ_S = per-Swing-state decay contribution, larger than ρ_I because Persian Gulf states have larger oil volumes and higher credibility signals. As n grows, the decay rate accelerates.
U_A(t)
U.S. payoff compounds down
U_A(t) = −H_t. As H decays, U.S. payoff becomes less negative in absolute terms but the strategic loss is irreversible. U.S. payoff = −H_0 × ∏(1−ρ_I−n_j·ρ_S) across all prior rounds. The product of decay factors compounds.
U_I(t) = G for all t
Iran's payoff is constant across every round. Its dominant strategy never changes, never decays, never requires additional action. Iran simply collects G each period.
H → 0 as t → ∞
As long as ρ_I + n_t·ρ_S > 0, H decays toward zero. The trap tightens automatically — even during a ceasefire, if yuan trades continue.
Decay is irreversible
Each CIPS transaction that clears is permanent operational history. When the crisis ends, the payment rail remains. H cannot be restored by negotiation alone.

Why Decay Compounds

01

Single-round decay: geometric, not arithmetic

H_{t+1} = H_t × (1 − ρ_I − n_t·ρ_S)

Each round, a fraction of remaining hegemony is lost — not a fixed amount. This geometric decay means the absolute loss slows as H approaches zero, but H never fully recovers. Compare with arithmetic decay (H_{t+1} = H_t − c): geometric decay is more realistic because the dollar's strategic value scales with its current share, not an absolute quantity.

02

Cumulative product formula

H_t = H_0 × ∏[j=0 to t−1](1 − ρ_I − n_j·ρ_S)

The product of all prior decay factors gives hegemony at round t. Each factor is less than 1, so the product strictly decreases with t. As n grows (more Swing states switch), the factors themselves shrink, accelerating the compounding.

03

U.S. payoff trajectory

U_A(t) = −H_t = −H_0 × ∏(1 − ρ_I − n_j·ρ_S)

U.S. payoff becomes less negative over time as H decays — but this is not improvement. A smaller |H| means less hegemony remaining to lose, not a recovery. The U.S. is not recovering from the trap — it is watching the strategic stakes of defending the dollar gradually fall to zero.

04

The asymmetry: Iran constant, U.S. compounds down

U_I(t) = G ∀t | U_A(t) = −H_0·∏(decay) → 0

Iran's payoff is a constant G every round. It requires no new action, no strategy change, no investment. The U.S. payoff compounds downward each round, requiring ever-greater diplomatic and military investment to defend a position that is shrinking anyway. Time works for Iran and against Washington.

t=0 · Start of crisis
H_0 = full hegemony
Dollar invoices 100% of Hormuz volume. CIPS has no operational war-time record. Status quo intact.
t=21 · Day 21 (current)
H_21 ≈ H_0·(0.97)^21 ≈ 0.53·H_0
At ρ_I=0.03 per day, 21 rounds remove ~47% of Iran's contribution to hegemony. India, Pakistan, Turkey deals add n_t·ρ_S.
n=1 · Saudi switches
Decay rate jumps from ρ_I to ρ_I + ρ_S
If Saudi Arabia begins yuan pricing, ρ_S ≈ 0.05 adds to the decay rate every round. H decays twice as fast.
t→∞ · Long-run
H → 0, U_A → 0, Iran still collects +G
Asymptotically, hegemony decays to near zero. Iran's payoff remains G. The petrodollar era ends not with a bang but with a product of decay factors.

Four Structural Changes Already Locked In

These effects are permanent. They do not reverse when the Hormuz crisis ends. Each represents an increase in the decay rate or a direct H reduction that no subsequent policy can undo.

H(t)/H_0 Decay Table

Fraction of original hegemony remaining after t rounds across different decay rates ρ_I + n·ρ_S. Current estimated zone highlighted.

t \ ρ_total0.020.040.060.080.100.15
>0.80 · minimal decay 0.60–0.80 · moderate decay 0.40–0.59 · significant decay <0.40 · severe decay ★ current estimated position

Five Decay Examples

Hegemony Decay Simulator

Watch H decay over rounds as decay rates and Swing state switches accumulate. Iran's payoff line stays flat at G every round.

0.030
0.050
0.0
8.0
10.0
H(t+1) = H(t)·(1−0.03−0×0.05)
Decay rate ρ_total
0.030
H after 10 rounds
H after 20 rounds
H after 50 rounds
Iran payoff (constant)
+8
Rounds to H = 50%
U.S. payoff −H(t) (decaying) Iran payoff +G (constant) Hegemony H(t)