And Caswell had let himself be distracted as they entered the danger zone. He was furious with himself, and determined to do better.
But all of the determination in the world wasn't enough to remove Nina, or the pain, from his thoughts.
Admiral Mehdi Baba-Janzadeh was called by some the father of the new Iranian navy. It was a role he cherished, and in which he took tremendous pride, though publicly he was careful to ascribe his success to the mercy and munificence of Allah. Within his inner circle of confidants, he liked to point out that Allah used human assets to achieve His goals, and clearly He was determined to turn the Persian Gulf into an Iranian lake.
Much of the recent growth of Iran's navy was due to his foresight and will. Long the weakest of Iran's military services, the navy had been all but destroyed during the long war with Iraq. Baba-Janzadeh had been appointed commander-in-chief of the Iranian navy just after that war's conclusion, and despite meddling by army and air force elements squabbling for scarce resources, he'd begun a major buildup that had continued for the past nine years.
He'd continued the buildup of long-range missile defenses — including the deployment of Chinese-built Silkworm HY-2 surface-to-surface missiles on Larak Island in the early 1990s. In 1992 he'd helped broker a deal with the People's Republic of China for Iran to purchase a fleet of seventy-ton Chinese patrol boats armed with Styx antiship missiles.
In 1993, at his urging, Iran had purchased the first two of an eventual six Russian Kilo submarines, along with eight minisubmarines from North Korea. Later, they'd purchased fifteen North Korean semisubmersible gunboats designed for commando operations. Following maneuvers in 2001, the Iranian merchant fleet was consolidated with the naval arm to improve overall fleet efficiency. Other additions and improvements swiftly followed, as Iran sought to replace the obsolescent foreign vessels of its regular navy with new and advanced designs produced in Iran. New destroyers, frigates, high-speed patrol boats, and finally the three Ghadir-class submarines. The goal — largely realized — had been to make Iran's navy self-sufficient and independent of foreign sources.
Five years later, in part as a reward for his efforts, Baba-Janzadeh was promoted to full admiral and appointed Minister of Defense, in charge of all of Iran's military forces. While his increased scope of responsibilities required that he relinquish much of the planning and execution of naval strategies to subordinates, he'd been able to have a hand in the selection of those subordinates. Rear Admiral Hamid Vehedi, the current commander of Iran's navy, had been a classmate of his at the naval academy and was a trusted friend. When Iran's supreme leader, the Ayatollah Ali Khamenei, had approached him to begin work on Operation Bold Fire, Vehedi had taken on much of the actual preparation.
Admiral Baba-Janzadeh stood in the Defense Ministry's basement communications center, a computer printout in his hand. The message had been sent by Vehedi, and it was one he'd been waiting for.
American submarine detected in Arabian Sea, the message read in part.
They were coming.
Things should start moving very swiftly now.
They'd found a tanker at last.
"Sonar contact now bearing three-five-five, Captain," the sonar officer said. "It is almost certainly a tanker emerging from the straits."
The weapons officer completed the TMA — the Target Motion Analyses — and turned to the captain. "Target speed six knots, range nine hundred meters, sir."
Captain Majid Damavandi stepped onto the control room dais. "Up periscope."
The periscope slid silently up out of the well, and Damavandi snapped down the handles and pressed his face against the eyepiece as it rose. He could see the green fog of brightly lit water, then the sudden burst of bright blue sky and sea as the head of the periscope broke through the surface. He did a careful three-sixty first, scanning for possible nearby threats that might have been missed by the sonar, before bringing the crosshair reticules onto the target.
Even a kilometer away, the target was huge. Its long, low hull with the far-aft white-painted superstructure was unmistakable, as was the flag hanging at the taff-rail.
"Liberian registry," Damavandi said. "Texan Star."
"Two hundred seventy-five thousand tons," Commander Reza Tavakkoli, the sub's executive officer reported, reading from the warbook. "Three hundred four meters loa. Despite the registration, it is American owned and operated."
"She will do," Damavandi said. "Maneuvering! Come left to zero-one-zero and increase speed to twelve knots. Engineer!"
"Yes, sir!"
"Prepare for snorkeling."
"Yes, sir!"
He felt, more than heard, the hum of the vessel's electric motor as Ghadir increased speed. Most of a submarine's time was spent remaining very, very quiet, and that meant remaining motionless, or idling along at a couple of knots, just enough to maintain steerage way.
There were times, however, when you simply had to make noise. Ghadir, like the Kilo-class submarines Iran had purchased from Russia, was not nuclear-powered. She was diesel-electric, which meant that she ran on the surface with noisy, air-breathing diesel engines, but underwater with quiet electric motors. Unfortunately, a sub running off her batteries could only do so for a limited time — in this case about eighteen hours.
Of course, on the surface and running the diesels— which also recharged the batteries — a sub was vulnerable, easily picked off by the enemy's ASW forces. The Germans had solved that problem for their U-boats by inventing the snorkel — essentially a tube sticking up above the surface from a submerged sub that lets it run the diesels while remaining underwater.
The down side of this was the fact that both diesel engines and the act of snorkeling itself are noisy, making a throbbing, pounding, hissing-wake racket easily picked up by the enemy's sonar systems.
The nine boats of Iran's submarine fleet all had been deployed to the narrow waters of the Gulf of Oman, just outside of the Straits of Hormuz. Their orders were to wait, remaining undetected, for the inevitable arrival of one or more American submarines. Savama, Iranian Intelligence, had already given the warning: The Americans' new guided-missile submarine Ohio had departed from the U.S. west coast three weeks before, almost certainly en route to the Gulf. When she arrived, the net of Iranian hunter-killers would close on her, trailing her closely and silently into Iranian territorial waters. And when that happened, Iran would have the excuse she needed to present to a watching world— the trigger that would launch Operation Bold Fire.
The problem was remaining undetected until Ohio arrived. Savama had also reported that at least one American SSN — the Pittsburgh—was in the Gulf already, and that others might be en route. Nuclear-powered, those submarines were unimaginably silent and deadly. How could Iran's fleet of diesel-electric boats remain submerged when — even if they didn't run their electric motors at all — they would still drain their batteries within a couple of days?
The answer had come from a Russian naval advisor working with Rear Admiral Vehedi at Bandar Abbas. Mask the noise you make beneath the louder noise of something else… in this case the Texan Star. Supertankers were loud.