the weak link

weak link

Someone or something considered inferior to the other parts of a group, series, or mechanism. The weak link in computer security is almost always the end user. Derek hardly ever comes to class, so I'm not surprised he was the weak link in our group project.
See also: link, weak
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

the weak link

the point at which a system, sequence, or organization is most vulnerable; the least dependable element or member.
See also: link, weak
Farlex Partner Idioms Dictionary © Farlex 2017

the weak ˈlink (in the ˈchain)

the point at which a system or an organization is most likely to fail: She went straight for the one weak link in the chain of his argument.
See also: link, weak
Farlex Partner Idioms Dictionary © Farlex 2017
See also:
References in periodicals archive ?
And he was dismissive of Graeme Swann's prediction he would be the weak link in Australia's attack.
The weak link here is THURSDAY/THUNDERY with only 50% invariable.
The weak link on any flight has to be the passengers, so how do we combat this?
"Japan should not be the weak link in the regional and global security framework where the US plays a leading role," Abe said.
Though occasionally amusing, the film feels like an episode of Friends and, sadly, writer/director/star Westfeldt is the weak link as an actress, lacking the easy charm of her impressive co-stars.
However, that's no longer the case, according to the latest alert by anti-virus firm Kaspersky Lab which yesterday warned the trusty Mac is "becoming the weak link in corporate security systems".
An injury crisis forced Alan Pardew to pick two full-back in the centre of defence and Norwich exploited the weak link to the full.
Scarlets coach Nigel Davies and skipper Matthew Rees call on the Scarlets'' forwards to prove they are not the weak link in the Scarlets machine.
Greece - the weak link in the eurozone chain with its tremendous debt and budget deficit - had to accept drastic austerity measures in exchange for its financial rescue by the European Union and the International Monetary Fund.
Despite the interpolation of the bullet, "my binding theme" cannot be separated, cannot be freed from "so many erroneous self-images." The weak link will be more consequential for this text and for another way of being than "these precedents," than what has "been determined." The possibility envisaged is of association no longer dependent on "amassing"--the amassing determined by conditions of production ("full-time occupation"), by industrialized warfare, and in the mass grave ("amassing / in a vault").
THE latest security fiasco at Birmingham airport (Mail, February 22) proves once again that regardless of how advanced the technology used to prevent further attacks is, the weak link continues to be the human being, on most cases under-paid, undertrained and over-worked, who is asked to operate it.
At the World Economic Forum in Davos, he also said countries like his "are being used as the weak link, if you like, of the eurozone."
Hobart, Jan 18(ANI): Australian skipper Ricky Ponting insists that struggling left-handed batsman Marcus North is not the weak link of the team.
FORMER Wallabies cult hero David Campese has branded struggling superstar Bryan Habana as the weak link in the Springboks line-up.
Davies, who hit into water, admitted she had been the weak link.