So Baha’u’llah himself acknowledged that the rulers rejected his message.The Bible does not say when during the messianic age peace would increase.
Baha'u'llah wrote that humanity could have had the Most Great Peace, but since the kings and rulers all rejected His message, we have had to settle for the Lesser Peace.
“Now that ye have refused the Most Great Peace, hold ye fast unto this, the Lesser Peace, that haply ye may in some degree better your own condition and that of your dependents.
O rulers of the earth! Be reconciled among yourselves, that ye may need no more armaments save in a measure to safeguard your territories and dominions. Beware lest ye disregard the counsel of the All-Knowing, the Faithful.
Be united, O kings of the earth, for thereby will the tempest of discord be stilled amongst you, and your peoples find rest, if ye be of them that comprehend. Should any one among you take up arms against another, rise ye all against him, for this is naught but manifest justice.”
Gleanings From the Writings of Bahá’u’lláh, pp. 253-254
Some of the prophecies for the return of Christ and how they were fulfilled by Baha'u'llah are depicted in the following 10 minute video.
How that prophecy was fulfilled can be seen in this video at the 6-minute mark.
Baha’is believe that the judging is being accomplished through the Universal House of Justice (UHJ).
What this means to a Baha’i is that in the future diverse religions and races will become comrades, friends and companions. The contentions of races, the differences of religions, and the barriers between nations will be completely removed, and all will attain perfect union and reconciliation. Eventually, there will be only one religion, the religion of God.
Clearly, Jesus did not fulfill Isaiah 11:6-9 but Jesus promised to fulfill Isaiah 11:6-9 when He returned.
John 10:16 And other sheep I have, which are not of this fold: them also I must bring, and they shall hear my voice; and there shall be one fold, and one shepherd.
The one fold and one shepherd is the promise to unite mankind, what Baha’u’llah came to do, among other things.
“My object is none other than the betterment of the world and the tranquillity of its peoples. The well-being of mankind, its peace and security, are unattainable unless and until its unity is firmly established. This unity can never be achieved so long as the counsels which the Pen of the Most High hath revealed are suffered to pass unheeded.” Gleanings From the Writings of Bahá’u’lláh, p. 286
“The utterance of God is a lamp, whose light is these words: Ye are the fruits of one tree, and the leaves of one branch. Deal ye one with another with the utmost love and harmony, with friendliness and fellowship. He Who is the Day Star of Truth beareth Me witness! So powerful is the light of unity that it can illuminate the whole earth. The one true God, He Who knoweth all things, Himself testifieth to the truth of these words.”
Gleanings From the Writings of Bahá’u’lláh, p. 288
Below is part of the commentary on Isaiah chapter 11, according to Abdu'l-Baha.
“In Isaiah, chapter 11, verses 1 to 10, it is said: “And there shall come forth a rod out of the stem of Jesse, and a Branch shall grow out of his roots: And the spirit of the Lord shall rest upon him, the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and of the fear of the Lord; And shall make him of quick understanding in the fear of the Lord: and he shall not judge after the sight of his eyes, neither reprove after the hearing of his ears: But with righteousness shall he judge the poor, and reprove with equity for the meek of the earth: and he shall smite the earth with the rod of his mouth, and with the breath of his lips shall he slay the wicked. And righteousness shall be the girdle of his loins, and faithfulness the girdle of his reins. The wolf also shall dwell with the lamb, and the leopard shall lie down with the kid; and the calf and the young lion and the fatling together; and a little child shall lead them. And the cow and the bear shall feed; their young ones shall lie down together: and the lion shall eat straw like the ox. And the sucking child shall play on the hole of the asp, and the weaned child shall put his hand on the cockatrice’ den. They shall not hurt nor destroy in all My holy mountain: for the earth shall be full of the knowledge of the Lord, as the waters cover the sea.”
This rod out of the stem of Jesse might be correctly applied to Christ, for Joseph was of the descendants of Jesse, the father of David; but as Christ found existence through the Spirit of God, He called Himself the Son of God. If He had not done so, this description would refer to Him. Besides this, the events which he indicated as coming to pass in the days of that rod, if interpreted symbolically, were in part fulfilled in the day of Christ, but not all; and if not interpreted, then decidedly none of these signs happened. For example, the leopard and the lamb, the lion and the calf, the child and the asp, are metaphors and symbols for various nations, peoples, antagonistic sects and hostile races, who are as opposite and inimical as the wolf and lamb. We say that by the breath of the spirit of Christ they found concord and harmony, they were vivified, and they associated together.”
But “they shall not hurt nor destroy in all My holy mountain: for the earth shall be full of the knowledge of the Lord, as the waters cover the sea.” These conditions did not prevail in the time of the manifestation of Christ; for until today various and antagonistic nations exist in the world: very few acknowledge the God of Israel, and the greater number are without the knowledge of God. In the same way, universal peace did not come into existence in the time of Christ—that is to say, between the antagonistic and hostile nations there was neither peace nor concord, disputes and disagreements did not cease, and reconciliation and sincerity did not appear. So, even at this day, among the Christian sects and nations themselves, enmity, hatred and the most violent hostility are met with.”
Some Answered Questions, pp. 62-63
The UHJ doesn't judge between the nations. It doesn't have such power and authority. Did they prevent or stop the war in Ukraine for example?
Yes, Jesus didn't fulfill Isaiah 11. Nor did Baha’u’llah. The unity has never been achieved. This is also what Abdu'l-Baha said.