Progress between EU and U.K. negotiators on contentious issues such as state aid and fishing rights is increasing the probability of a limited trade agreement by the end of the year. However, London’s ongoing attempts to circumvent certain aspects of the Withdrawal Agreement that it reached with Brussels last year could still thwart such a deal. The European Union is worried that the United Kingdom will use state aid to increase the competitiveness of its companies vis-a-vis their continental rivals, while London has pledged to restrict EU access to its fishing waters. Both issues have been obstacles to a deal since the beginning of trade talks in March, but in recent days there have been signs of potential compromises....