By Alison Smale and Michael D. Shear
The United States and its closest allies on Monday cast Russia out of the Group of 8 industrialized democracies, their most exclusive club, to punish President Vladimir V. Putin for his lightning annexation of Crimea, while threatening tougher sanctions if he escalates aggression against Ukraine.
President Obama and the leaders of Canada, Japan and Europe’s four strongest economies gathered for the first time since the Ukraine crisis erupted last month, using a closed two-hour meeting on the sidelines of a summit meeting about nuclear security to project a united front against Moscow.
