So, it's over.  Joe Biden and Vladimir Putin wrapped up their sessions in Geneva, Switzerland, and the deeper assessment of the American President's foreign trip has begun.  He had quite a timetable: G7, Boris Johnson, Queen Elizabeth, the EU, NATO and, finally, the critical one-on-one with Putin.There are general developments that we can take away from this past week.The claim that "America is Back" seems to have some merit.  Various global leaders, including PM Justin Trudeau, spoke of a renewed hope that in a time of great challenge internationally, the United States has moved back into the pole position to direct diplomacy, partnerships, and the more complex work of confronting democracy's deniers.A distinct sense emerged that a renewed energy was infusing the G7, prompting them to speak of upgrading a united COVID response, of cooperating on the ever-present climate change challenge, and recommitting to opposing pro-hate movements.For many, all this is welcome news following years of uncertainty. A new Pew poll, taken this past week, revealed that while 12 significant world economies had expressed only 17% belief that Trump was doing the right thing as President, Biden's numbers shot up to 75%.  A new sense of optimism has emerged.But there are dangers, and for countries like Canada that rely heavily on global partnerships and trade, the central place of an agenda-ridden America could spell trouble.While Donald Trump made much of his "America First" strategy, Biden's "America is Back" claim at the G7 implies that that the two slogans might not be all that much different.  Either way, the United States will seek dominance.  Like it or not, the new friendliness will require Canada to make adjustments.Joe Biden's extensive investments of trillions of dollars in infrastructure and the expansion of social programs are an apparent attempt to grow his country's economic might once again.  The emphasis seems less about global trade than the U.S. going head-to-head with its economic competitors.  And that includes Canada.While the world's focus seemed to be on the Biden-Putin summit, America's clear enemy and competitor on numerous levels is China.  The EU, however, remains lukewarm concerning the Chinese threat while the U.S. is increasingly focused on competing with China for global dominance.  How it manages the challenge will have effects on its allies.Though a collective sigh of relief emerged from the numerous meetings in Europe, the reality remains that Donald Trump is far from gone.  That was apparent this week as Biden worked hard to overcome the damage of the past four years with America's friends.  While repeatedly stressing his "America is Back" mantra, it's also true that Donald Trump is alive and present.  Republicans have failed to move on from the Trump era, making him a continuing player on the global stage.As outgoing German Chancellor Angela Merkel put it in her final statement of the G7 sessions: "Look, the election of Joe Biden as U.S. president doesn't mean that the world no longer has problems." Some of those problems have to do with the fact that with the past President still active, there remains a troubling uncertainty that the America of Trump still exists, a kind of mischievous interloper.  Should the American mid-term elections next year swing away from the government, as is typical, both the Senate and the House could once again be dominated by Republicans, making delivering on Biden's plans a great uncertainty.Consequently, America itself can't entirely shed its recent past, which means the future is cloudy.  The setting of the new Biden agenda on the global stage will be in danger of collapsing if Republicans surge.  The partners were fully aware at the G7 that the threat of this return to the past is real.  It served as a dark undercurrent in all the sessions, despite all the bravado.The Trump era forced America's allies to move away from remaining simple followers of the U.S. agenda and setting futures of their own. Biden's attempt to bring them all back in under the American tent, while seeming obvious this week, isn't fully put in place.  Canada and Britain seem to like the idea, but countries like Germany and France remained lukewarm.These aren't the old days, where both Democratic and Republican presidents embraced the idea of America's centrality in global dealings.  Donald Trump broke that pattern, leaving other nations to forge their independent futures.  While Biden was ever the professional diplomat, the reality is that he has trouble trumpeting his agenda when his own domestic opposition remains strong enough to challenge his every move.Reshaping a world that includes economic recovery, rising debt Russia, populism, military threats, and democratic decline remains a daunting task and will take a united and robust alliance to prevail.  The problem for the G7 is that they can claim it but can't prove it. Significant uncertainties remain, and Canada will be strengthened or undermined depending on the outcomes of these problems.The world didn't just get better this week because leaders maintained they were back together.  It will take hard work to strengthen a world that was already in trouble before Donald Trump's rise. Canada's role in that challenge remains to be determined and defined.Glen Pearson was a career professional firefighter and is a former Member of Parliament from southwestern Ontario. He and his wife adopted three children from South Sudan and reside in London, Ontario. He has been the co-director of the London Food Bank for 35 years. He writes regularly for the London Free Press and also shares his views on a blog entitled “The Parallel Parliament“. Follow him on twitter @GlenPearson.