Is it permissible to partner with someone who has not paid taxes or debts in their country, claiming that their country is unsafe, knowing that the partnership will be in a lawful business?

It is permissible to engage in a partnership with a Muslim who has offered a share in a permissible trade, for the default is that what he possesses is his property. And even if he is unjust by not fulfilling rights, that does not prevent engaging in partnership with him in a permissible trade.