BACKGROUND
World War I (WWI or WW1 or World War One), also known as the First World War, was a global war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918. More than 9 million combatants were killed, a casualty rate exacerbated by the belligerents' technological and industrial sophistication, and tactical stalemate. It was one of the deadliest conflicts in history, paving the way for major political changes, including revolutions in many of the nations involved. Britain declared war on Germany on 4 August 1914, following an "unsatisfactory reply" to the British ultimatum that Belgium must be kept neutral. Read more >>
CARTOON
The cartoon by Peter Brookes from The Times shows a group of British soldiers 'going over the top' armed only with rifles fitted with bayonets. Certain death awaits them as they approach the barbed wire and enemy fire. One of the soldiers comments to his companion, "At least in a hundred years there'll be no more slaughter, Carruthers ..."
COMMENT
The soldier's comment is, of course, meant to be ironic. One hundred years on, the slaughter continues all around the world (Syria, Gaza, Ukraine, Iraq, etc., etc.). 'The war to end all war' was a term for World War I first used in August 1914. Originally idealistic, it is now used mainly in a disparaging or ironic way.
GRAMMAR
Note the contraction "there'll be" for "there will be", which is the future form of "there is". The soldier could also have said "there won't be any more", which does, however, sound less elegant.
NOTES
1. The sepia look of the cartoon is meant to recall the photos of the time.
2. Carruthers is a posh name which suggests the cliché of the upper-class soldier who has enlisted for idealistic reasons.