Thanks to Peto.
As ever, a great puzzle from Peto. Good mix of clue types and nothing too obscure. A pleasant distraction from the proceedings of the day.

ACROSS
1. Passive American in retreat before long (6)
SUPINE
US< (American, <in retreat) before PINE (long)
4. Tory to attract scorn (8)
CONTEMPT
CON (Tory) + TEMPT (to attract)
9. Enter for example without resistance (6)
PIERCE
PIECE (example) without R (resistance)
10. A Luddite tactic to make teabag so explosive (8)
SABOTAGE
(TEABAG SO)* (*explosive)
12. Launch cut short after crack by McCartney perhaps (4,4)
ROCK STAR
STAR[t] (launch, cut short) after ROCK (crack)
13. Monkey avoiding extremely savage rodent (6)
MARMOT
MARMO[se]T (monkey, avoiding S[avag]E (extremely))
15. Aim at getting unctuous fool finally dismissed (4)
SEEK
S[l]EEK (unctuous, [foo]L (finally) dismissed)
16. Jazz fan running around naked in a place of entertainment (7)
CABARET
CAT (jazz fan) running around BARE (naked)
20. Young girl assuming Rene’s coming around as usual (7)
GENERAL
GAL (young girl) assuming RENE< (<coming round)
21. Went from the centre of Warwick by river heading west (4)
WEED
[War]W[ick] (centre of) by DEE< (river, <heading west)
25. God’s close to the front taking in quiet place of retreat (6)
ASHRAM
RAMA (god, close to the front i.e. ARAM) taking in SH (quiet)
26. Disparage translation of great ode (8)
DEROGATE
(GREAT ODE)* (*translation of)
28. Criminals involved with breaking into houses (8)
VILLAINS
IN (involved with) breaking into VILLAS (houses)
29. Relaxed with a book about Haiti’s capital (2,4)
AT HOME
A TOME (a book) about H[aiti’s] (capital)
30. Great German city’s unlimited distribution of gifts (8)
LARGESSE
LARGE (great) + ESSE[n] (German city, unlimited)
31. Information discovered in tent not initially top-priority (6)
URGENT
GEN (information) discovered in [y]URT (tent, not initially)
DOWN
1. Put down for buffet supper on board (8)
SUPPRESS
(SUPPER)* (*buffet) on board (SS)
2. Clergyman’s come to during Republican uprising (8)
PREACHER
REACH (come to) during REP< (Republican, <uprising)
3. Most precise directions to protect diamonds over time (6)
NICEST
N S (directions) to protect ICE (diamonds) over T (time)
5. Stone wall essentially needing work (4)
OPAL
[W]AL[l] (essentially) needing OP (work)
6. Hypocritical of cadet when originally at fault (3-5)
TWO-FACED
(OF CADET W[hen] (originally))* (*at fault)
7. An oppressive atmosphere caused by Farrow’s mother (6)
MIASMA
MIA’S (Farrow’s) + MA (mother)
8. Act upon your original agreement (6)
TREATY
TREAT (act upon) + Y[our] (original)
11. Declare to be true after chum makes a fuss (7)
PALAVER
AVER (declare to be true) after PAL (chum)
14. Stiff ask at the outset to support scoundrel over upcoming clergyman (7)
CADAVER
A[sk] (at the outset) to support CAD (scoundrel) over REV< (clergyman, <upcoming)
17. Individual copies to be returned before class (8)
SEPARATE
APES< (copies, <returned) before RATE (class)
18. Refrain from interfering with unaccompanied bags recently turning up (3,5)
LET ALONE
LONE (unaccompanied) bags LATE< (recently, <turning up)
19. Then read out, Devotee . . . . (8)
ADHERENT
22. . . . . to wonder as one of poet’s lines is deleted’ (6)
MARVEL
MARVEL[l] (poet, one of his lines deleted)
23. Arrest in recital causing anger (6)
CHOLER
“COLLAR” (arrest, “in recital”)
24. Engaged in lining Dutch colonist’s hat (6)
BOATER
AT (engaged in) lining BOER (Dutch colonist)
27. An unexpected advantage after commencement of task (4)
ONUS
[b]ONUS (unexpected advantage, after commencement)
A bit stiffer than I expected for a Monday (though on that subject, I liked the definition of 14d).
I got off to a flying start but struggled in the SW corner, and entered a number unparsed, such as 22 .
I also enjoyed the definition of 21, along with 13, 31, 6 and 23.
Thanks to Peto for an entertaining if tricky puzzle (for me, at least) and to Teacow for parsing those I could not.
Thanks, Teacow, you confirmed two answers that I thought were correct but I had difficulty with the definitions.
1A” to me “supine” relates to a physical position whereas “passive” is more of a mental mood.
3D: I cannot reconcile “nicest” as a synonym of “most precise”. I’m the nicest person in the room but I waffle a lot!
Thanks for the blog, I really enjoyed this, agree with the list from Diane@1, I will add LET ALONE for the misleading bags.
Peter@2 , nice is one of those words where the meaning has changed a lot over time, see the large entry in Chambers. Originally it meant precise or exact, perhaps surviving in nicety.
Yes, Roz. I remember Simeon Potter describing the surprising journey of various words in “Our Language”; nice was one that always stayed with me.
The second of two un-Mondayish puzzles, though this wasn’t quite as difficult as the Soup in the Guardian. I managed to solve everything in the end but didn’t quite parse LARGESSE correctly (incidentally, I think there’s a minor typo in the blog – it should be [e]SSE[n]). Out of ignorance I didn’t know SLEEK, my last in, as a sense of ‘unctuous’. I agree with Roz @3 [sorry for mis-spelling your name the other day], about the intended sense of NICE at 3d.
I liked the story told by the surface for MARMOT and the should have been simple but wasn’t PIERCE.
Thanks to Peto and Teacow
Quite a few rather approximate equivalents, I thought, such as PIECE/EXAMPLE, TASK/ONUS, PRECISE/NICE, CRACK/ROCK, UNCTUOUS/SLEEK. I’d not heard of Marvell, nor CHOLER.
Geoff @6 Andrew Marvell is very early , just try one poem – To His Coy Mistress.
No problem WordPlodder, I assumed it was the correcting thing, I sometimes get Fox.
Roz, I just love Andrew Marvell. His poems actually rhyme. I have to say that my favourite is “The Fair Singer” – very short but deep and meaningful and one that I can relate to my own life.
Also, thanks for the explanation of “nice:. When I lived in England the OED was the definitive source of words. It’s only been in the last few years that Chambers has reared its head in crossword-land.
In 12a how does rock = crack?
Thanks
Oldham@3 I am afraid this is drugs slang. Lumps of crack cocaine are called rocks.
Peter @8 I think the OED is the definitive source in general use of the language.
Chambers for crosswords has been used at least since Ximenes in the 1940s .
Azed , since 1972, specifies Chambers for each puzzle he sets.
It is a single volume containing a vast number of words and relatively affordable.
I need a replacement for my Chambers 93, second hand copies, virtually unused , are less than £5.
Roz, that was very brave of you revealing your knowledge of street drugs, revealing that crack cocaine and rocks are the same thing.
This is the most fun that I have had since looking up “Playtex” and “Gossard”. Both hints provided by Roz. Thanks Roz. Great photos for a male.
Thanks Peto for the challenge. I managed to complete this though I couldn’t parse SEEK or MARVEL; I hadn’t known that WEED=went; I was tempted to write in “peed” but there was no justification for a “p.” Besides, this is Peto, not Paul. Clues I liked best included SUPINE, LET ALONE, and ONUS. Thanks Teacow for the blog.
[Diane: It was good to see you commenting on Serpent’s crossword on Saturday. Wire (Leonidas) had an excellent puzzle on Sunday if you’re so inclined.]
We didn’t know ‘rock’ = ‘crack’ but ROCK STAR was the obvious answer to 12ac once we had all the crossing letters. The rest went in without any real problems. The symmetrically placed eye rhymes, PALAVER and CADAVER, reminded us of Everyman. Others we likes included SABOTAGE and VILLAINS.
Thanks, Peto and Teacow.
Peter@2: SUPINE is often used in a figurative sense, as in someone being too supine to do anything about a problem.
Roz@3: Further to your comment on NICE, we remember being discouraged in school English lessons from using the word, an example to avoid being sometging like ‘It was a nice day so we went for a nice walk and had a nice picnic then we had a nice ride home on a nice bus …’ and so on. (And of course we’d have to put an apostrophe before ‘bus.)
Roz, allan_c et al, this was the nicest blog of a nice puzzle full of nice clues.
Thanks Peto for the fun, and Teacow for the help with parsing 25a ASHRAM (I didn’t know the god) and 18d LET ALONE (which I should parsed and which became a favourite once you explained it).
Allan@13,
My English teachers did likewise so I’ve always been wary of the word ‘nice”… and then there’s the French connection – often used here – which can cause a slip-up too.
[Tony@12,
Thanks, once again, for the heads-up].