Judah is returning to their homeland, but they find old enemies still living in the area too.  The Samarians had separated with the northern kingdom of Israel, and entertained other gods.  You may recall that they are resented by the Jews even though Jesus made a point about a good Samaritan.  These were not good Samaritans.

But it came to pass, that when Sanballat heard that we builded the wall, he was wroth, and took great indignation, and mocked the Jews.  And he spake before his brethren and the army of Samaria, and said, What do these feeble Jews? will they fortify themselves? will they sacrifice? will they make an end in a day? will they revive the stones out of the heaps of the rubbish which are burned?  Now Tobiah the Ammonite was by him, and he said, Even that which they build, if a fox go up, he shall even break down their stone wall.  Hear, O our God; for we are despised: and turn their reproach upon their own head, and give them for a prey in the land of captivity:  And cover not their iniquity, and let not their sin be blotted out from before thee: for they have provoked thee to anger before the builders.  Nehemiah 4:1-5

Sanballat is a historical figure who claimed to be loyal to the Persian king, but later turned to their Greek enemies.  Then he turned against the Greeks too.  For now he just provokes his old enemies of Judah.  He mocks Judah and they petition God against the Samarians.  http://www.livius.org/saa-san/samaria/samarians.htm 

So built we the wall; and all the wall was joined together unto the half thereof: for the people had a mind to work.  But it came to pass, that when Sanballat, and Tobiah, and the Arabians, and the Ammonites, and the Ashdodites, heard that the walls of Jerusalem were made up, and that the breaches began to be stopped, then they were very wroth,  And conspired all of them together to come and to fight against Jerusalem, and to hinder it.  Nevertheless we made our prayer unto our God, and set a watch against them day and night, because of them.  And Judah said, The strength of the bearers of burdens is decayed, and there is much rubbish; so that we are not able to build the wall.  Nehemiah 4:6-10

After all the punishment that Samaria suffered from the prophets and enemy armies, they are still a thorn to Jerusalem.  When people turn away from God they can really turn against him.  One can see this in the world today and also in modern Israel.  The land is intermingled with Moslems, Jews, and Christians as it was of many beliefs then.  It was hard then as now to know where the threat would come from.

And our adversaries said, They shall not know, neither see, till we come in the midst among them, and slay them, and cause the work to cease.  And it came to pass, that when the Jews which dwelt by them came, they said unto us ten times, From all places whence ye shall return unto us they will be upon you.  Therefore set I in the lower places behind the wall, and on the higher places, I even set the people after their families with their swords, their spears, and their bows.  And I looked, and rose up, and said unto the nobles, and to the rulers, and to the rest of the people, Be not ye afraid of them: remember the LORD, which is great and terrible, and fight for your brethren, your sons, and your daughters, your wives, and your houses. Nehemiah 4:11-14

The Jews who live near their enemies are working against them with words of discouragement!  Confidence in God comes from a relationship that works both ways.  Some people of Samaria recognize God but they are not entirely faithful to him.  The people of Judah were prepared to give themselves wholly to God and they knew his assurances for confidence.  His sheep know his voice.  They are bold to work while armed for battle.

And it came to pass, when our enemies heard that it was known unto us, and God had brought their counsel to nought, that we returned all of us to the wall, every one unto his work.  And it came to pass from that time forth, that the half of my servants wrought in the work, and the other half of them held both the spears, the shields, and the bows, and the habergeons; and the rulers were behind all the house of Judah.  They which builded on the wall, and they that bare burdens, with those that laded, every one with one of his hands wrought in the work, and with the other hand held a weapon.  For the builders, every one had his sword girded by his side, and so builded. And he that sounded the trumpet was by me.  And I said unto the nobles, and to the rulers, and to the rest of the people, The work is great and large, and we are separated upon the wall, one far from another. Nehemiah 4:15-19

Nehemiah notices the distances between the defenders, a weakness when under attack.  They made plans to be ready in that event.  Today the believers are few in number but strong in faith for our battles.

In what place therefore ye hear the sound of the trumpet, resort ye thither unto us: our God shall fight for us.  So we laboured in the work: and half of them held the spears from the rising of the morning till the stars appeared.  Likewise at the same time said I unto the people, Let every one with his servant lodge within Jerusalem, that in the night they may be a guard to us, and labour on the day.  So neither I, nor my brethren, nor my servants, nor the men of the guard which followed me, none of us put off our clothes, saving that every one put them off for washing. Nehemiah 4:20-23

The shofar calls the defenders and the Lord to battle.  They work to rebuild Jerusalem with one hand on their weapons.  They live within the walls at night for security.  Even when they slept at night they remained dressed for battle. 

The reconstruction of Jerusalem today proceeds in mixed company with unrest being the norm.  Everyone may be called to serve in the military.  But like then, faith is mixed and often incomplete.  Few in Israel recognize that their Messiah is available to answer the trumpet now.  Many are secular Jews, as disconnected as their enemies.  Others are bound by religious traditions that David would not recognize.  But God has a remnant who know their master’s voice.  The temple will be restored.