Don’t overestimate yourself, young man!
Hearing William's words, Steven fell into deep thought. After a moment of silence, he said, "This land first appeared within our national borders. How can we allow other countries to just enter freely?"
William replied indifferently, "If that's really your concern, don't you have connections with those Soulmancer Guilds? You could make an agreement. If anyone disobeys the rules, go in and kill them one by one."
Although there were no nations when William first became conscious, having lived on this continent for nearly a century, he naturally had an affection for it.
"That... might work," Steven said, his mouth twitching. In that case, they would indeed need the help of many Soulmancer Guilds.
Even if agreed to let other countries send people in, it was unlikely they would allow them to bring heavy weapons or aircraft carriers blatantly.
Agreeing to let their people in would most likely mean admitting only superpowered individuals.