First of all, Spain had nothing to gain by threatening her. The delicate balance of power that had been established would not tilt in their favor through such a brazen act. They couldn't induce political chaos in England since there was a separate joint king, whose authority would remain undiminished even in her absence, ensuring continuity of governance and a swift, terrible retribution should any harm befall her.
Moreover, by now Spain must be yearning for peace, if only from exhaustion. The country's treasury had been drained by years of costly conflicts across multiple fronts. They had many enemies more important than England—the Ottoman Empire pressing at their Mediterranean territories, rebellious provinces in the Low Countries consuming resources and manpower, and rivals circling their colonial possessions like hungry wolves. A provocative move against her would only serve to unite their opponents and further isolate Spain in European affairs.
