Admiral Leach and the decision to fight for the Falklands

What does it mean to say Admiral Leach saved Thatcher from herself during the Falklands War?

Leach assured Thatcher that Britain could and should retake the islands when others doubted a successful operation was possible, giving military backing to her instinct to fight. The claim that he politically saved her can be overstated.

Thatcher's instinct to respond was separate from confidence that the operation was feasible. Many advisers believed the war could not be won, while First Sea Lord Admiral Sir Henry Leach supplied the Royal Navy's clear assessment that Britain could fight. Without that assurance she might have lost the war, with serious political consequences. The claim that Leach saved her can be overstated, but his intervention gave military backing to her determination to act. Political resolve needed a credible military option before it could become policy.