David Cameron has recently let it be known that his favourite poet is Wilfred Owen. This isn't surprising. The poets of the first world war are drip-fed into every kind of school across the country, and the extra-literary appeal of their writing (the courage, the suffering, the devastation it describes) makes them irresistible to pupils who are not otherwise much interested in poetry. Many benefits follow, and some difficulties  among them, an unduly rigid idea of the historical moment, and a sense that the Owen/Sassoon style is the only way to write war poetry, which means a lot of excellent second world war poetry suffers by comparison. It also means that books about the first war poets have appeared in a steady stream, as generation after generation tries to explain and assimilate their power. Some of these, like Paul Fussell's The Great War and Modern Memory, and Geoff Dyer's The Missing of the Somme, shed fresh light on the old tragedy. A great many others simply tramp through the dreadful mud, hoping that sympathy will stand in for insight.

Harry Ricketts's Strange Meetings features a good deal of dutiful tramping, and a few gleams of fresh lighting. It doesn't so much say new things, as say old things in a new way. Noticing how many of these poets met while fighting or recuperating, and how often those that survived the war maintained (often tempestuous) relationships after it had ended, Ricketts tells the story of their friendships so as to highlight mutual influences, envies, admirations and disgruntlements. It makes the poems seem linked to one another as well as their circumstances, and adds a sense of intimacy as well as common purpose to the strategies they adopt.

It also highlights a couple of generally undervalued aspects. One relates to Rupert Brooke. According to received wisdom, Brooke was turned very quickly from being the poster boy of the first world war (those beautiful but sugary portraits by Schell, those sonnets which said that going to war was like being a swimmer "into cleanness leaping") into a reprehensible kind of innocent: his critics say he should have anticipated the horrible reality of fighting. Ricketts allows us to see that while this is a pretty fair summary of the change in his reputation, his example lingered a good deal longer than the standard anthologies tend to suggest (because they squeeze him into their opening pages). We see him being admired by the young Sassoon; drawing Edward Thomas into definitions of his self, and of acceptably un-jingoistic patriotism  vital for his own poetry; influencing the love life and philosophy of Vera Brittain; and even, at a later stage of the war, coaxing from Ivor Gurney "a complicated mixture of tribute and riposte".

All this amounts to a significant reappraisal of Brooke, and makes him seem a more potent figure than has recently been admitted. But such is the fractured nature of Strange Meetings that Ricketts cannot easily find the space to capitalise on his assessment. A similar problem affects his other striking emphasis  which concerns homosexuality, and the homoerotic. When Jon Stallworthy published the first full-length biography of Owen in 1974 he failed to say anything about this  drawing a veil that has since been pulled aside by Dominic Hibberd, among others. Our understanding of Owen, our sense of the deep origins of his sympathy with fellow-soldiers, and our appreciation of his feelings about "the pity of war" in general, have therefore been significantly deepened.

At the same time, a great deal of new information has come to light about Sassoon, the young Robert Graves and Edward Marsh, the editor of Georgian Poetry, and his friends Robbie Ross and Charles Scott Moncrieff, which shows they were vitally shaped and stimulated by knowledge of the gay milieu. Ricketts synthesises all this pretty effectively, and is alert to cryptic or glancing references  such as Owen's allusion to "the wildest beauty in the world", in "Strange Meeting". It means we can see an important network of associations linking personalities, as well as poems, with greater clarity  and therefore appreciate the true character of the poems with a properly respectful tenderness.

In other respects Rickett's book is more useful as a series of reminders ("lest we forget") than anything else. He extends the range of previous and similar surveys by including the chapter on Vera Brittain and her lover Roland Leighton. He does justice to Ivor Gurney's poems, which have only been given their just deserts in the last generation or so. He does well to include the story of Robert Nichols, who in the early years of the war was widely reckoned to be the "next Rupert Brooke", or even for some the "next Keats", but whose life turned into a series of increasingly embarrassing lunges for poetic power, before ending in Winchelsea with a rich wife and a tiny readership.

Forgotten, but not gone. As Ricketts points out, the famous Hollywood epitaph fits Nichols all too well, but he was by no means the only poet-survivor to experience loss of power and prestige. Sassoon and Graves and Blunden kept a healthy audience by augmenting their poems with prose accounts of the war but even Sassoon fell from public view during the middle part of the century, and for a long time (and still?) Graves's poetic reputation trailed behind his reputation as a prose writer.

It wasn't really until the 1960s that the kind of reverence now given to the war poets began to take shape. What made this possible? Unfortunately Ricketts doesn't even ask the question (which might be answered by thinking about the relationship between the war-as-subject and Britain's declining role in the world, among other things). Instead, he gives a summary account of the soldier poets of the first world war exhibition, put on by the Imperial War Museum in 2002.

After cataloguing the often very touching exhibits, which he rightly remembers as objects at "a site of saints' relics", he concludes: "They showed us human nature tested up to and beyond breaking point. They showed us courage, anger, humour, compassion. Their picture of war is the one we carry with us. They remain our contemporaries. They remind us what we are capable of." This is all true enough  but it is also familiar to the point of banality. In being so, it achieves the state that books on this subject should avoid at all costs  that of seeming comfortable.

Andrew Motion's The Cinder Path is published by Faber.