The Falklands War represents a big part of the Thatcher mythos, to the extent that it's become part of the media's operational code that you can't divide the two. This is founded on a couple of facts, and more myths. The fact is that it undoubtedly helped her win re-election from a fairly ugly starting point. (The counterfact is that, had it gone the other way, as was possible, she would almost certainly have been doomed.)
The myths, though, are much more productive. The first one is that the war represented a personal achievement for Margaret Thatcher, that her strength of purpose and decisions were crucial to success. The second is that the war somehow represented Thatcherism, for good or ill depending on partisan allegiance.
The official myth of Thatcher begins with the notion, as retailed in her memoirs, that the invasion came as a total surprise and no power on earth could prevent it. But, on the 2nd April, 1982, Admiral Sir Henry Leach, First Sea Lord and Chief of the Naval Staff, came in full uniform to an emergency inner cabinet and briefed that a carrier group could sail within 48 hours. Thatcher, inspired, swept aside the objections of pitiful wets to order the sinking of the Belgrano and win the war, with the vital support of the Americans.
It's a myth. As Brian Barder points out, it is simply not true that "No one predicted the Argentine invasion more than a few hours in advance". Regular intelligence warnings had arrived for months, the South Georgia crisis had arisen, and by the 2nd of April, the Royal Navy had been increasing its readiness state for several days. On the 26th of March, when a specific intelligence warning from a source in Argentina arrived, the first shipping movements had already begun (RFAs Greenleaf and Fort Austin being set in motion south). The key value was the time it took for a Valiant or Swiftsure-class submarine to sail south at maximum speed - Spartan made it in a week and a half, sailing on the 27th March. To put it another way, sailing the sub on the 23rd would have put her in Falklands waters on invasion day. On the 20th of March, the government ordered Endurance to South Georgia with Lieutenant Keith Mills's marines aboard.
It was the obvious moment to take action, but the Thatcher cabinet was torn between the will to wound and the fear to strike. The Argentine admiral in command, Rear-Admiral Allara, had always assumed that the presence of a submarine would kibosh the operation. Unlike in 1977, when the Callaghan government deployed HMS Dreadnought, the chance was passed up. The government kept dickering, while the Navy staffs made quiet preparations.
On the 29th of March, Fleet HQ at Northwood warned off the carriers and Sandy Woodward's escort group in the Mediterranean, whilst setting up a 24-hour operations watch for the South Atlantic. The military must accept a little criticism here - "order, counterorder, disorder" was rife, with 40 Commando, Royal Marines, being stood-to for the South Atlantic with no word of how to get there, stood down, stood to again, and stood down again without anyone bothering to tell 3 Commando Brigade or Mike Clapp's amphibious-warfare HQ about it.
Finally, the government took charge once the damage was done. But, as we discussed in Myth 1, it was far from clear about what it wanted. Northwood didn't issue a clear aim until the 12th of May, probably because it didn't have one itself. This begs the question of whether the Chiefs of Staff had one, which begs the question of what the government thought it was doing. (It also reflects badly on the Chiefs that they didn't insist on a clear grand strategy, or come up with one themselves.)
Decisive? Hardly. But the Thatcher government did at least avoid some of the possible traps. In April and early May, there was a lot of military quackery abroad, with wild suggestions of "making a bang in the South Atlantic" (as Michael Rose liked to say) by crash-landing Hercules aircraft full of SAS onto the Stanley airfield in order to....er...kidnap the Argentine commander, or something, or of launching a Vulcan raid on Buenos Aires, or (for Christ's sake) blowing up the Exocet plant in Toulouse, despite the fact the French intelligence services were helping to prevent any more of the missiles reaching Argentina. Fortunately, they built on the rock and not upon the sand.
Then there was the temptation of relying on the Americans, who had little interest in seeing their pet dictator walloped, or of grabbing for a compromise solution. There was the US offer of the loan of an aircraft carrier to be manned by the Royal Navy, which given the timescales involved can only realistically have been a white elephant intended to scupper the expedition. (Imagine all that requalification for the 3,000 ratings involved, on equipment never seen before in the RN.)
Whatever judgment is drawn on Thatcher should be tempered by the fact she could rely on some outstanding civil servants, specifically Sir Frank Cooper as MOD Permanent Secretary and Sir John Hunt as Cabinet Secretary, although the shaky performance of the Chiefs counterweighs this. Whatever, it's pretty clear she did better than Tony Blair or John Major would have, but not as well as Jim Callaghan, who scored the jackpot by heading off the war in the first place.
On the second, broader topic, a detailed consideration shows that to win the war, Thatcher had to rely on a whole swath of institutions and cultures she had not the slightest regard for. Early on, the MOD(Navy) called in the chief executive of P&0, acting for the whole shipping industry, and the National Union of Seamen, to thrash out the conditions under which merchant ships and their crews would serve. It was concluded that they would get a 150 per cent bonus and stay under their normal discipline until action was joined. A less Thatcherite solution is hard to imagine.
Hence, the scene south of Ascension, where Atlantic Conveyor drew alongside the fleet tanker RFA Tidepool to refuel underway. This had of course never been imagined for the big container ship. As the transfer was going on, Soviet Tu-95 Bear reconnaissance planes flew overhead several times to take photos. The Navy, the RFA, and her master hoped the Russians would show the images to someone who would spot the key detail - Atlantic Conveyor was the leader, with the fleet tanker keeping station on her, not the other way around.
Similarly, just to get started, Devonport Dockyard had to turn around RFA Stromness, which they had just completed stripping of stores and equipment before putting her in mothballs. This had taken weeks, but she was readied for sea and loaded with a huge range of supplies (a portable fuel-handling terminal, thousands of feet of aluminium runway planking) and several hundred Marines within days. The BLACK BUCK Vulcan raids relied, as the V-bombers always had done, on direct interworking between the engineering wings and the aerospace industry.
It's fair to say, I think, that Margaret Thatcher cared politically for nothing less than the merchant fleet, the unions, shipwrights, or for that matter, the Navy. A lot of military people look back to her with nostalgia, but then, by definition they were younger then. And, with the exception of the Falklands, it wasn't a bad time to be a soldier - overseas postings were either sunny (Belize, Hong Kong, Cyprus) or dull but comfortable, like the vast bulk of the army's bases in Northern Germany, with good beer, kebabs, and duty-free perks. And very little action.
No, this was more like the death ride of the post-war consensus. Some people, like Fort Austin's captain Sam Dunlop, had done the whole of the second world war.
None of this prevented the media, and Thatcher's spin doctors, from rolling the whole thing into the Thatcher myth - the photos of her riding a tank during Exercise LIONHEART-84, endless pompous blather. Meanwhile, the merchant navy vanished, as did the shipyards, BAE converted itself into a machine focused on Saudi shenanigans, and the military didn't lay down another amphibious ship until Ocean in 1995.