The enmity between the two sides who collide again this weekend never seems to subside. Even last week, Jurgen Klopp tried to place Gary Neville's annihilation of the European Super League breakaway clubs within the narrative of Manchester United's dislike of Liverpool.
But when it comes to existential matters — preservation of these two great clubs — the relationship has always been far more complicated than that. It would perhaps be an exaggeration to describe what has existed between them at certain critical moments as 'sympathy' but there is certainly empathy and mutual understanding.
It's why some United fan groups made exploratory calls to Liverpool when the Super League plans became known last week, asking whether they might join protests at Old Trafford this weekend.
Manchester United fans are still furious with the Glazer family over their ownershipInsurance Loans Mortgage Attorney Credit Lawyer
Liverpool supporters have also vented their anger at Fenway Sports Group in recent weeks
The idea of a co-ordinated protest was dropped when the ESL plans were ditched but some Liverpool fans may still make the 30-mile trip east up the M62 on Sunday.
This spirit of co-operation between the two is nothing new. United fans have never forgotten 2005. Their club had just been bought by the Glazers when they faced Arsenal in the FA Cup final and their opponents' fans mocked them mercilessly.
'Sold To The USA,' was the Arsenal reworking of Bruce Springsteen's hit that day. It did not go unnoticed among those of a United disposition that Liverpool fans in no way contributed to the ridicule.
United were the first of the rivals to go under American ownership through the Glazers in 2005
It was soon after that Tom Hicks and George Gillett bought Liverpool, in another highly leveraged American buy-out which ultimately put the club in grave jeopardy.
'There was no point laughing at them because we knew it could happen to us. What United went through, we went through, only on a different scale,' says Jay McKenna, former leader of the highly-respected Spirit of Shankly (SoS) supporters' union which drove the campaign to oust Hicks and Gillett. 'Arsenal fans now know that, too.'
The outcome of the Hicks and Gillett effort contrasted with United's Green and Gold 2010 campaign, which fizzled out as the team remained serial winners under Sir Alex Ferguson. But it could have been a different story if Liverpool's 2005 Champions League triumph had led to further glories.Insurance Loans Mortgage Attorney Credit Lawyer
Not long after Liverpool came under control of U.S businessmen George Gillett and Tom Hicks
It also helped that manager Rafael Benitez publicly challenged the Americans in a way Sir Alex Ferguson never did the Glazers at Old Trafford. There was respect from the United fans for what Liverpool supporters accomplished back then.
The improbable fraternity between the two reaches back further — to the three and a half years after the Second World War when City's Maine Road was also United's home ground — Old Trafford having been bombed. For their part, City had made donations in 1902 when Newton Heath — precursor to United — were in trouble. The two clubs' directors were always close.
A month after the Munich disaster in 1958, Liverpool, then a Second Division side, offered United the services of two of their players to tide them over. In August 1971, when United fans' hooliganism caused them a two-game ban from Old Trafford and left them in need of a temporary home, Liverpool stepped up. United's only 'home' game at Anfield ended with a 3-1 win over Arsenal. The other game was played at Stoke's Victoria Ground.
United and Liverpool fans may come together on Sunday in