Over the 90's LY dropped the route to ARN several times because of security reasons, but in 1997, LY returned to ARN with a weekly nonstop flight (LY373) and another one via HEL (LY375/373).
In the winter of 2000 the airline dropped the route again as a lack of demend, but on the summer of 2000, LY returned once again to ARN for the Summer time, operating 2 weekly, nonstop, 757s flights.
Then, in the end of Summer 2000, the Intifada had started and tourism to Israel had declined, LY dropped ARN & HEL, but it did continue it services to CPH.
Today, the route to CPH is being operated twice a week with anything between the 742 to the 757.
The airline did say that this route would be dropped on September, but it doesnt look this way, it seems like LY will stay at CPH.