Responsibility for going over to the States (4)
I believe the answer is:
onus
'responsibility' is the definition.
(onus is a duty or responsibility)
'going over to the states' is the wordplay.
'going' becomes 'on' (both can mean functioning or activated).
'over' says to put letters next to each other.
'to the states' becomes 'US' (abbreviation for the United States).
'on'+'us'='ONUS'
'for' acts as a link.
(Other definitions for onus that I've seen before include "'Responsibility, task or burden (4)'" , "albatross?" , "Capulet opponent (R&J)" , "Obligation - charge" , "Weight of responsibility" .)