If you’re asking about hints, that requires a lot more time and thought. However, there are some similarities between them that I can briefly go over. In my opinion, it makes for excellent shipping material.
For starters, they’re both incredibly insecure individuals. They want to make friends but have trouble doing so, and don’t always recognize that what they’re doing is wrong.
Ex: America being nosy and poking into everyone’s business, and Russia’s cruel treatment of other nations under his rule.
Personally, what I would use as a good focal point for conflict is the fact that they both think everyone hates them:
That’s a very good point! I never realize it before! Cool 🙂
Some additions for the anon.
Some common grounds I see similar from both of them is how they’re double-faced / hiding their true feelings/loneliness behind their smiles / their childish like attitude towards other nations.
As for historical side, though it’s not really emphasized much on hetalia, Himaruya did make a revolutionary war strip featuring APH Russia in it. And though it’s such a small panel for him in it, it represents how they started out even before APH America became a nation; APH Russia was one of nations who supported him in revolutionary war.
Also at American Civil War era, Russia also was one of few nations who supported the Union (though idk if Himaruya ever focused on it and made it official strip). And Russia’s support at Civil War era even discussed among historians to be one of factors that made France and Great Britain reluctant to support Confederate and this, making it possible for Union to win the Civil War. (for the history lovers, you could check it here http://www.voltairenet.org/article169488.htmlhttp://www.voltairenet.org/article169488.html)
So what makes this angsty for this pairing is that, their bilateral relationship started out really great in imperial russian era, until russian revolution started and changed Russia to USSR. Just imagine how their hundreds years of warm friendship suddenly turnt 180 degree in just few years. And basically made them act passive aggressive like this most of the time on Himaruya’s strip:
I think it’s canon that despite their passive aggressive bickering, APH Russia still wants to become friend with APH America. Like we could see here in this official strip where APH Russia imagines if every nations turns to children (including APH America here), there would be no conflict of interests and they could become friend.
While idk if APH America also feels the same way towards APH Russia, I think his nonchalantness in butting his way to APH Russia’s business just like how he acts towards other nations despite their long history of passive aggressiveness in hetalia universe is also kind of a hint that APH America also still wants to be friend with APH Russia.
There’s also that one scene in APH Paint it white where APH America went straight to APH Russia for his “sidekick” and not to other nations.
Idk, I might be biased since I’m a RusAme fan and all but I think those hints based on how they interacted with each other in canon shows that they actually want to be friends with each other despite their passive aggressiveness in canon.
And knowing how they actually started out great as friends in Imperial Russian era like how I explained above, I think it’s kind of bittersweet and shows how friendship in Hetalia universe is kind of fragile and depends on the “interest” each nation has. How hundreds of years wonderful bilateral relationship between USA and Imperial Russian Era could decay so quickly in just few years after Russia changed his boss and become USSR. Maybe that could be the “angsty” aspect that anon search for in canon, idk.
Bravo to anyone who reads this long post until the end btw, you guys rock 🙂