A strike in capital, perhaps, is disaster (8)
I believe the answer is:
calamity
'disaster' is the definition.
(I've seen this before)
'a strike in capital perhaps' is the wordplay.
'strike' becomes 'lam' (to 'lam' means to hit hard).
'in' is an insertion indicator.
'capital perhaps' becomes 'city' (capital is a kind of city).
'a'+'lam'='alam'
'alam' inserted within 'city' is 'CALAMITY'.
'is' is the link.
(Other definitions for calamity that I've seen before include "15 [JANE] the frontierswoman" , "A disaster, like Western heroine Jane" , "Disaster for wild west Jane" , "Blow" , "Musical set in Deadwood" .)