[8] In 2008, Tolkin joined the United States national side as defence coach, which saw him play pivotal part in their 2011 Rugby World Cup campaign.

His ability to get the best out of players, which saw him specialize in talent identification and player development serving as a talent recognition selector in 2001 for former USA Head Coach Tom Billups,[9] saw Tolkin promoted to Head Coach in 2012, taking over from Irishman Eddie O'Sullivan.

Tolkin set out with the stated aim of qualifying for the 2015 Rugby World Cup as Americas 1, and progressing out of the Pool Stages.

In August 2015, the United States lost on aggregate 40–20 to Canada to fail to qualify for the World Cup as Americas 1.

Later that year, in front of a sold out Soldier Field, USA lost 74–6 to the All Blacks, the first test between the nations in America since 1913.

[19] Though the U.S. did qualify for the 2015 Rugby World Cup, Tolkin failed to achieve a win in the tournament, losing to Samoa 25–16, Scotland 39–16, Japan 28–18 and South Africa 64–0, which saw the States finished last in their group.

Following the 2015 World Cup, Tolkin returned to coaching the New York Athletic Club, achieving an undefeated record for the 2016 season.