Can you please give the Scriptures which tell us that the Abrahamic Covenant, through which God gave the Jewish people the land of Israel, is conditional upon their behavior?
Ask you and shall receive!
Deut 6:17-19 You shall diligently keep the commandments of the Lord your God, His testimonies, and His statutes which He has commanded you. And you shall do what is right and good in the sight of the Lord, that it may be well with you, and that you may go in and possess the good land of which the Lord swore to your fathers, to cast out all your enemies from before you, as the Lord has spoken.
The problem with your demand is that it presupposes an incorrect understanding of the Abrahamic Covenant, and Covenants in general.
Repeatedly, our LORD reminds the people that the only reason they will inherit the Land is because of the Promise that our LORD made to Abraham, Isaac and Jacob. in this passage from Deuteronomy, God is going to give them the Land because He is Faithful and True - not because the wanderers deserved anything. But if you note, the passage seems to say that keeping the land was contingent on their keeping the promises. In fact, upon entry into the Promised Land, Joshua asked the people to choose to follow God or to reject Him. For not even a full generation the people sort of obeyed God, and indeed God was faithful to Abraham, Isaac and Jacob and indeed they inherited ALL the land that God had promised them. Yet within a generation the children of Israel rebelled, and as you can see, with the possible exception of the days of Solomon, have never again had full possession of the Land, and because the Covenant was not strictly about the physical land (Heb 8), but of the heavenly Kingdom (Hebrews 11:10).
Today's Israel is worse than those of Joshua's day, in that they observe none of the Temple rituals and have rejected God's Son. Since God has already fulfilled the physical land promise, there is no expectation or obligation on God's part to honor any land deals that the Zionists impose on God. Since the Abrahamic Covenant was a type of the "city which hath foundations, whose builder and maker is God... that is heavenly" (H 11:10,16; 12:22,28; 13:14; Rv 21:14), the New Jerusalem is the Church - those who are of Faith.
Today's Israel is (spiritually) blind and must remain blind until after the rapture or they would be taken. When the spiritual famine comes, they will go in search of spiritual food, and they will find Christ. Joseph and his brothers will be reunited.
The Abrahamic Covenant is an unconditional covenant. God made promises to Abraham that required nothing of Abraham. Genesis 15:18-21 describes a part of the Abrahamic Covenant, specifically dealing with the dimensions of the land God promised to Abraham and his descendants.
The actual Abrahamic Covenant is found in Genesis 12:1-3. The ceremony recorded in Genesis 15 indicates the unconditional nature of the covenant. The only time that both parties of a covenant would pass between the pieces of animals was when the fulfillment of the covenant was dependent upon both parties keeping commitments. Concerning the significance of God alone moving between the halves of the animals, it is to be noted that it is a smoking furnace and a flaming torch, representing God, not Abraham, which passed between the pieces. Such an act, it would seem, should be shared by both parties, but in this case it is doubtless to be explained by the fact that the covenant is principally a promise by God. He is the one who binds Himself. God caused a sleep to fall upon Abraham so that he would not be able to pass between the two halves of the animals. Fulfillment of the covenant fell to God alone.
God determined to call out a special people for Himself through whom He would bring blessing to all the nations. The Abrahamic Covenant is paramount to a proper understanding of the kingdom concept and is foundational to Old Testament theology. (1) The Abrahamic Covenant is described in Genesis 12:1–3 and is an unconditional covenant. There are no conditions attached to it (no “if” clauses, suggesting its fulfillment is dependent on man). (2) It is also a literal covenant in which the promises should be understood literally. The land that is promised should be understood in its literal or normal interpretation—it is not a figure of heaven. (3) It is also an everlasting covenant. The promises that God made to Israel are eternal.
http://www.gotquestions.org/Abrahamic-covenant.html
The Abrahamic Covenant was entirely and completely dependent upon God and was not conditional in any way, shape or form on the behavior of the Jews.