Does the Dhamma suggest to change external unfavourable conditions

Lord buddha didn't refuse economical and physical development of a person while he practices dhamma..By reading Kutadanta Sutta and Vyagghapajja Suttayou can get a comprehension on these things.. And otherwise for politicians can refer saptha aparihai dharma and dasa raja dharma,in order to understand their duty

The Buddha did not intend monks to participate in politics, as seen in DN 2:

"Whereas some brahmans and contemplatives, living off food given in faith, are addicted to talking about lowly topics such as these — talking about kings, robbers, ministers of state; armies, alarms, and battles; food and drink; clothing, furniture, garlands, and scents; relatives; vehicles; villages, towns, cities, the countryside; women and heroes; the gossip of the street and the well; tales of the dead; tales of diversity [philosophical discussions of the past and future], the creation of the world and of the sea, and talk of whether things exist or not — he abstains from talking about lowly topics such as these. This, too, is part of his virtue.

However, the Buddha did intend for lay people to participate in constructive nation building, in accordance with the Dhamma in DN 16:

At that time the Venerable Ananda was standing behind the Blessed One, fanning him, and the Blessed One addressed the Venerable Ananda thus: "What have you heard, Ananda: do the Vajjis have frequent gatherings, and are their meetings well attended?"

"I have heard, Lord, that this is so."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline.

"What have you heard, Ananda: do the Vajjis assemble and disperse peacefully and attend to their affairs in concord?"

"I have heard, Lord, that they do."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline.

"What have you heard, Ananda: do the Vajjis neither enact new decrees nor abolish existing ones, but proceed in accordance with their ancient constitutions?"

"I have heard, Lord, that they do."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline.

"What have you heard, Ananda: do the Vajjis show respect, honor, esteem, and veneration towards their elders and think it worthwhile to listen to them?"

"I have heard, Lord, that they do."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline.

"What have you heard, Ananda: do the Vajjis refrain from abducting women and maidens of good families and from detaining them?"

"I have heard, Lord, that they refrain from doing so."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline.

"What have you heard, Ananda: do the Vajjis show respect, honor, esteem, and veneration towards their shrines, both those within the city and those outside it, and do not deprive them of the due offerings as given and made to them formerly?"

"I have heard, Lord, that they do venerate their shrines, and that they do not deprive them of their offerings."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline.

"What have you heard, Ananda: do the Vajjis duly protect and guard the arahats, so that those who have not come to the realm yet might do so, and those who have already come might live there in peace?"

"I have heard, Lord, that they do."

"So long, Ananda, as this is the case, the growth of the Vajjis is to be expected, not their decline."