First off, what is "toxic masculinity"? That seems to depend on who you ask. Radical feminists tend to say that all masculinity is toxic. However, more rational feminists describe destructive, abusive, irrational behavior being celebrated as "masculinity" as toxic.
Wikipedia describes toxic masculinity as including, "...dominance, devaluation of women, extreme self-reliance, and the suppression of emotions," and goes on to list such traits as misogyny, homophobia, and violence as aspects harmful to others. Meanwhile, self-reliance and stifling emotions are considered harmful to the self. It also says, "Other traditionally masculine traits such as devotion to work, pride in excelling at sports, and providing for one's family, are not considered to be toxic."
Some of these allegedly toxic attributes are not per se destructive, at least in my doubtlessly inferior masculine perspective, but what do I know? Women need me like fish need bicycles, right? But all joking aside, self-reliance and stoicism in the face of emotional trauma do have their place. A man should know how to inflict violence upon those who intend violence toward him, and be prepared to do so if necessary. Some things are beneficial in moderation, and only unhealthy in excess or when misapplied.
Time to stop mansplaining, though. I do not want to dismiss the concept out of hand. I think there is room to consider it from a masculine perspective and explore how our views of "masculinity" have warped our understanding of the world. And, of course, I want to make as many people as uncomfortable as possible, so let's use nationalism as our lens. What if toxic masculinity and nationalism share similar misguided ideologies?
Nationalism is typically understood as not merely extreme patriotism, but the belief that one's government is superior to that of other countries and has the right, nay, the duty to dominate in any international matter. Those not blessed to have been born within its borders are devalued as humans, and viewed with suspicion if not outright hostility. Foreign trade is deemed a threat to national self-reliance. The only emotions allowed for outsiders is somewhere between pity and contempt. There is believed to be a duty to work for the benefit of the State, and any form of dissent outside the narrow range of acceptable opinions is a treasonous threat. The violence of the military is celebrated, and yet any equal response by any foreign military is condemned as an atrocity.
How is this not utterly toxic to humanity? How does this help us achieve technological or economic progress for the benefit of the everyman? Sorry I just used a masculine-only general term. I'll try to reform! How does the massive consumption and destruction of wealth by governments benefit us individually, or society as a whole? Why are people on the other side of a political line unworthy of participation in society?
"Can anything be more ridiculous than that a man has a right to kill me because he lives on the other side of the water, and because his ruler has quarrel with mine, although I have none with him?"—Blaise Pascal
Like toxic masculinity, there are elements of nationalism that could be viewed as a cancerous growth from something beneficial. Human beings are social creatures. Community is an important concept. Again, violence in self-defense is a necessary and productive behavior to thwart destruction from external threats. However, nationalism exaggerates these and other beliefs to comic proportion and then demands we comply with its absurd conclusions. Take a long moment to reflect on your reaction whenever an argument is couched in terms of national identity, political expedience, or patriotic necessity. You may realize you've been hit with a wave of toxicity instead of reason and evidence.