Bilateral Signals

Twelve readings of the dependence graph, in six pairs.
Each signal asks one question of the same data — who relies on whom, where there is no alternative, and which way the ties are moving.
Dependence— who relies on whom
Leverage
Most depended upon
Who the world depends on. The nations others cannot do without.
Exposure
Most dependent
Who depends on the world. The nations most reliant on others to function.
Concentration— where there is no alternative
Chokepoints
Hardest to replace
Leverage with no substitute. Supply the world cannot route around.
Fragility
Hardest to diversify
Exposure with no substitute. Reliance that cannot be diversified away.
Balance— the shape of the tie
Imbalance
Greatest upper hand
Who holds the upper hand. The net direction of dependence in a relationship.
Reciprocity
Most mutual / most lopsided
How mutual the tie is. Balanced give-and-take against one-sided reliance.
Structure— position in the network
Connectors
Greatest bridging role
Who bridges the system. The nations linking otherwise-separate clusters.
Blocs
Largest behavioural cluster
Who clusters with whom. The de-facto groupings revealed by behaviour, not by treaty.
Presence— breadth of engagement
Reach
Widest presence
Who is everywhere. Influence measured by breadth of presence, not depth.
Orphans
Most isolated
Who stands apart. The nations weakly tied across every domain.
Change— the direction of travel (arriving with the historical series)
Momentum
Rising fastest
Who is rising. Ties deepening fastest — broadly, or in a single decisive pivot.
Decoupling
Unwinding fastest
Who is pulling apart. Dependence unwinding fastest across the network.

Every signal is computed from the same directional dependence graph; only the question changes. Concentration signals use a Herfindahl measure of supplier diversity; structural signals (Connectors, Blocs) use network centrality and community detection — see Methodology for the algorithmic choices and their limits.