There are no problems which we cannot solve together, and very few that any of us can settle by himself.

Lyndon B. Johnson (1908-1973) American politician, educator, US President (1963-69)

Speech (1964-11-28), Press Conference, LBJ Ranch, Johnson City, Texas
    (Source)

Regarding the Atlantic Alliance (NATO). Variant: "There are no problems we cannot solve together, and very few that we can solve by ourselves."