Obligation of an Islamic state

Read the tafsir of the verse below (an-naml:36 & 37) and my comment after that.

The Gift and the Response of Sulayman

More than one of the scholars of Tafsir among the Salaf and others stated that she sent him a huge gift of gold, jewels, pearls and other things. It is apparent that Sulayman, peace be upon him, did not even look at what they brought at all and did not pay any attention to it, but he turned away and said, rebuking them:

[أَتُمِدُّونَنِ بِمَالٍ]

("Will you help me in wealth'') meaning, `are you trying to flatter me with wealth so that I will leave you alone with your Shirk and your kingdom'

[فَمَآ ءَاتَـنِى اللَّهُ خَيْرٌ مِّمَّآ ءَاتَـكُمْ]

(What Allah has given me is better than that which He has given you!) means, `what Allah has given to me of power, wealth and troops, is better than that which you have.'

[بَلْ أَنتُمْ بِهَدِيَّتِكُمْ تَفْرَحُونَ]

(Nay, you rejoice in your gift!) means, `you are the ones who are influenced by gifts and presents; we will accept nothing from you except Islam or the sword.' - Tafsir Ibn Kathir.

My note:
1. The requirement of jihad isclear especially when an Islamic state is established.
2. The response of Sulayman and what Prophet SAW did after he had established Madinah were two points that support the point above.
3. In fact, US did the same - accept democracy or else war.