How should Buddhism be introduced to a country?

Such concerns have obliviously resulted in the degeneration of Buddhism over the past 2,600 years.

Simply teach the Dhamma; starting with DN 31 as mundane and SN 56.11 as supramundane.

The scripture say the Dhamma is taught primarily to people who are gods & humans rather than to people dwelling in the hungry ghost, animal & hell realms.

And if there’s anyone of whom it may be rightly said that a being not liable to delusion has arisen in the world for the welfare and happiness of the people, for the benefit, welfare and happiness of gods and humans, it’s of me that this should be said.

MN 4

Being unaware of these three fires, This generation delights in personal existence. Unfree from the bonds of Māra They swell the ranks of hell, Existence in the animal realm, Asura-demons and the sphere of ghosts. Iti 93

This generation delights in attachment, is excited by attachment, enjoys attachment. For a generation delighting in attachment, excited by attachment, enjoying attachment, this/that conditionality & dependent co-arising are hard to see. This state, too, is hard to see: the resolution of all fabrications, the relinquishment of all acquisitions, the ending of craving; dispassion; cessation; Unbinding. And if I were to teach the Dhamma and others would not understand me, that would be tiresome for me, troublesome for me.' MN 26

The Dhamma should be taught to others only when five qualities are established within the person teaching. Which five?

[1] The Dhamma should be taught with the thought, 'I will speak step-by-step.'

[2] The Dhamma should be taught with the thought, 'I will speak explaining the sequence [of cause & effect].'

[3] The Dhamma should be taught with the thought, 'I will speak out of compassion.'

[4] The Dhamma should be taught with the thought, 'I will speak not for the purpose of material reward.'

[5] The Dhamma should be taught with the thought, 'I will speak without hurting myself or others.'

AN 5.159

The Vinaya says:

Go forth, o bhikkhus, for the good of the many, for the happiness of the many, out of compassion for the world, for the benefit, for the good, for the happiness of gods and men. Let not two go by one way. Preach the doctrine that is beautiful in its beginning, beautiful in its middle, and beautiful in its ending. Declare the holy life in its purity, completely both in the spirit and the letter. There are beings with little dust in their eyes who are ruined because of not hearing the Teaching. There will be those who understand.

Mahākhandhaka

To avoid ambiguity about the above, suttas such as MN 95 say:

Here, Bhāradvāja, a bhikkhu may be living in dependence on some village or town. Then a householder or a householder’s son goes to him and investigates him in regard to three kinds of states: in regard to states based on greed, in regard to states based on hate, and in regard to states based on delusion.

As he investigates him he comes to know: ‘There are no such states in this venerable one. The bodily behaviour and the verbal behaviour of this venerable one are not those of one affected. And the Dhamma that this venerable one teaches is profound, hard to see and hard to understand, peaceful and sublime, unattainable by mere reasoning, subtle, to be experienced by the wise. This Dhamma cannot easily be taught by one affected by greed, hate & delusion.’

In summary, if our facial complexion looks as though we are depressed, not pure and not joyful, we cannot spread the Dhamma effectively to gods & men.

Also, about the phrase: "There are beings with little dust in their eyes...", MN 26 says:

I saw beings with little dust in their eyes and with much dust in their eyes, with keen faculties and with dull faculties, with good qualities and with bad qualities, easy to teach and hard to teach, and some who dwelt seeing fear and blame in the other world.

For example, those on the internet who watch p**n and endorse sex with prostitutes dwell not seeing fear and blame in the other world. They have dust in their eyes.

One doesn't introduce Buddhism to a country. One introduces Buddhism to people, and people carry it with them where they go.

Spreading Buddhism is like spilling water; it goes where it will, without much regard for borders, and nourishes those it touches.

Good householder,

By generosity, respect and goodwill toward the Gems, through the carrier (or vehicle) which is the Sangha of Monks, this Dhamma-Vinaya would have foundation to get introduced and maybe established within the country.

The teachings of the Buddha, and its spreading deeper into a certain community in the world, would always have to be introduced by the Sublime Buddha's disciples, the Sangha.

Establishing of the (Re-)legion requires foremost the Sangha of Bhikkhus and could take place when invited by the reigning King of the country, or leader of a certain community. Such would mean: There is Dhamma-Vinaya present in this country or community.

As for the current situation, there are for the most part, no more Kings, leader, really in charge and as far as I'm aware, while having or doing die off in old countries, Dhamma-Vinaya hasn't been established anywhere else in the world.

And as far as I'm aware, there is only one country left where a dhammic King still reigns, where most laws are still in harmony with the Dhamma-Vinaya and no disputes over its sublimeness have yet arisen. However, it might also end after this generation.

Soon, if negative tendencies continue, there will be no more Sangha present, no more Dhamma-Vinaya, but just a worldly attempt at an inferior copy: Buddhism.

One, seeing still an opportunity, should, if wise, go to join the holy life within an institution that will soon decay and one will less likely be able to go forth without such support.

Hurry up, whenever an opportunity is found. Those heading for liberation shouldn't wait.