Today two young men, twenty-four years of age, born in London, Mohmed Ahmad Abdulkarim and Nouman Essghir, were charged under the law the British call the National Security Act and brought before the judges. One, as DW reports, is accused of conduct that would give aid to the spies of a foreign power — they suspect Parthia; the other is said to have entered a prohibited place in August to the harm of his country. These are charges, not yet proven: so the prosecutors allege, and so the court will decide.

Meanwhile seven men said to have been arrested in this affair were released on bail, before others were seized. The American president Donald Trump openly condemned this: he says he is surprised they were released, and that he himself would never have done such a thing. Against him, Laurence Taylor, who commands the cohorts set against traitors, defended his plan: his decisions, he said, can at times appear senseless to those outside, but there is always a reason behind them; time is needed to turn intelligence into evidence; by this road came swifter progress, better evidence, and at last the charges themselves; and the hand of the Parthian state in these matters is, he says, highly likely.

Let both be heard. I know what delay can do: "one man, by delaying, restored the state to us." But Fabian delay is a weapon stored up for its moment, not a prefect's idleness; and the question a camp prefect asks first is this: while those released men wandered free, who was watching them? The reports do not say. There is a graver wound: the charge says the prohibited place was entered in August, yet the alarm was not raised until September. A wall is judged not by the last man who crosses it, but by the first.

Nor is that all. Some twelve of those planes they call B-1 Lancers, which carry more deadly weight than any cohort of ballistae, the Americans withdrew from this base because of "some threats", as their president says; and this while the house they call Number Ten, from which the British prime minister usually speaks, was insisting the place was safe. Two masters, two voices. An ally who pulls back his eagles casts a truer vote than any letter sealed with oaths. Cui bono? If the cohorts' suspicion is true, Parthia — which declares the bases from which missiles are hurled at its own land to be legitimate targets — has gained the field without a battle; yet Parthia denies it did anything, and the reports so far show no proof linking the accused to their foreign taskmasters. Report is not yet proof. I sat long on the tribunal lest I condemn any man on a prefect's suspicions; I stood long on the frontier lest the gate be left open while we argue.

But one must seek the cause, not the chance: from this base, as both sources relate, missiles were hurled at Parthia. A province that lends its soil to another's war invites that war onto its own threshold. Augustus warned that the empire be kept within its boundaries; I gave back Mesopotamia, which Trajan had taken, because what you cannot hold you should not even occupy. It is not mine to judge the Americans' war; but a magistrate who receives a foreign army on his soil owes his citizens a doubled watch, and the reports do not show that it was doubled.

The remedy is at hand, and it is not new. Let a rampart be drawn around the base, as I drew a wall at the far edge of Britain "to divide the barbarians from the Romans"; let the posts be inspected, the soldiers drilled in peace, the watchmen who slept punished, and those who gave warning rewarded; let there be one voice on the safety of the place, and let the allies' words agree with their deeds. A frontier is not drawn on a map but stands in vigilance; where the guards sleep, the wall is a tomb.