Protective Trade

Protective Trade places guards along the trade routes between two realms. Deals in transit between the two of you survive enemy bombing, whoever fires the strike: the guard is on the route itself, so it holds against every attacker, not only against your partner. It also cuts the cost of sending a trade deal to that partner to a third of the usual daily rate.

The guard covers deals with that partner only. Anything you have in transit to another realm can still be bombed, and so can goods you have listed on the trading market.