Good reporting here by the Guardian:
http://www.guardian.co.uk/usa/story/0,12271,1146190,00.html
Key paras:
"In an annual evaluation of his performance - dated, coincidentally, the very same day, May 2 - they conceded that they couldn't actually evaluate his performance, because they hadn't seen him for months."
"But the administration's release this week of those new records from Bush's stint in the national guard - the US equivalent of the territorial army - seems only to have given the controversy new life."
"Ii is hard to escape the suspicion that Bush got an easy ride through the guard. At the time he did his years in uniform, his father was a prominent Texas congressman, a fact not lost on his commanding officers, who seemed, in the latter years of his service, disinclined to demand regular attendance. "I'd have to have been an idiot not to know about [Bush's parentage]," says Lieutenant-Colonel Albert Lloyd Jr, a retired personnel officer whose signature is on documents released by the White House this week apparently confirming Bush's service. "Bush is sworn into the National Guard and there is his father, Congressman Bush, standing beside him. It was a good chance for unit publicity.""
"However rosy the future president's situation, though, the second half of 1972 marked the beginning of a black hole in his life. It was a period marinated in alcohol, and apparently as hazy to Bush at the time as it would prove to reporters who later tried to reconstruct it. In December that year, according to many reports, he took his 16-year-old brother Marvin drinking, prompting an aggressive confrontation in which George Jr famously offered to fight his father "mano a mano". (In 1976, he was convicted of drunk driving.) There have long been rumours of drugs: the president has never admitted taking them, but his carefully worded denials have never encompassed the years before 1976. "When I was young and irresponsible," the candidate often recited during the 2000 campaign, "I was young and irresponsible." And when it came to his military service, according to National Guard records that are not clearly refuted by this week's White House releases, Bush simply fell off the radar."
Even if the White House wins the argument about exactly what happened in Texas and Alabama in 1972 and 1973, it is not clear that the furore will evaporate. Some interpretations of the documents suggest that Bush realised the gravity of his situation and hurried to make up his minimum service requirements, ending his time in the military with his duties fulfilled. But that might not be sufficient, says Joshua Marshall, a Washington journalist who edits the influential weblog www.talkingpointsmemo.com and writes for the Washington Monthly. "The backdrop is that even the White House's story is not a good one," he says. It is widely agreed, he points out, "that the president was a son of a congressman who used his connections to get a cushy deal ... So the Democrats wouldn't take much of a hit even if the whole White House story was true. It's still a story of using your connections to get out of Vietnam."